Home

Manual for the Ares Modeler Module

1. Element Params Yariables Global Params description Rdist 304 8 mm Do E3 Do mm fo Dbaff 100000 mm E z R 0 MKS Ray lke Num 1 eu 4 Ww p Ready NUM Copyright 2012 2013 McIntosh Applied Engineering LLC 85 70 current buffer 60 T jae lt o 50 7 D A 40 Ares 30 100 1000 10000 Frequency Hz Hit the CALC button or the F5 key to generate the graph above This is the response of the speaker without a resonant port Let s save this curve for later reference Select the graph element press the A button to copy the data into buffer A select the checkbox to the left of the A button and type speaker w o port into the buffer s description The graph is now as shown below Plotting buffers A Speaker w o port Copyright 2012 2013 McIntosh Applied Engineering LLC 86 70 current buffer speaker w o port 60 S A lt 2 50 7 D A 40 A 30 res 100 1000 10000 Frequency Hz Add a radiating circular port and a dual summer to the model as shown below Pressing the CACL button or F5 key will generate the following graph Note that the output at 950 Hz has been significantly increased but at the cost of less output below 700 Hz This is a typical tradeoff for a bass reflex speaker design
2. Mechanical resistance of the membrane This represents the damping or energy loss for the membrane or plate This will not be computed from the plate or membrane equations but must be manually entered A value of 0 will represent an undamped membrane resonance Typically you ll either measure R or estimate its value by selecting a value that provides good fit at resonance between model and a system response measurement Diameter of the membrane or plate Number of membranes or plates in parallel Thickness of the membrane or plate material Used in the fundamental equations for computing the plate or membrane s 1st mode frequency Density of the membrane or plate material Used in the fundamental equations for computing the plate or membrane s 1st mode frequency Young s modulus of the plate material Used in the fundamental equations for computing the plate s 1st mode frequency Poisson s ratio of the plate material Used in the fundamental equations for computing the plate s Ist mode frequency Tension of the membrane material Used in the fundamental equations for computing the membrane s Ist mode frequency Resonant frequency of the membrane or plate s first mode Computed from M and C Copyright 2012 2013 McIntosh Applied Engineering LLC 71 acoustical material An element representing a lossy acoustic material such as a fabric or felt that can be characterized by a flow resistance or a complex frequency depend
3. 6 Copyright 2012 2013 McIntosh Applied Engineering LLC 87 80 current buffer 70 speaker w o port 60 T 50 A lt 2 40 7 E 30 20 10 Ares 100 1000 10000 Frequency Hz To help optimize the choice of the rear volume and port size select the volume element 4 and iterate on its height to produce the following graph 90 80 70 _ 60 z A 50 2 2 40 A current buffer H 25 mm a 20 current buffer H 43 75 mm current buffer H 62 5 mm 20 current buffer H 81 25 mm current buffer H 100 mm 10 speaker w o port r Ares 100 1000 10000 Frequency Hz Now you can choose a rear volume height that best delivers the response you desire Copyright 2012 2013 McIntosh Applied Engineering LLC Note that the data in buffer A is hard to see as its color is blending in with the other iteration curves We can make it stand out by using the Set buffer line button in the graph parameters to bring up the following dialog box and change the line weight for buffer A to 2 Our baseline curve in buffer A is now easier to see E Line type solid Line weight The graph now 90 8
4. Acoustic Modeler Module The Ares Modeler performs a linear frequency domain lumped parameter analysis of electrical mechanical acoustical and thermal systems The main focus of the model 1s acoustical modeling and acoustical components To launch the modeler open the New Modeler menu and select Modeler as shown below _ Ares Acoustic System Ares1 Peon Modules Window Help Coordinate Mapper Flow Impedance Measurement Frequency Response Measurement Modeler developed by Mcintosh Applied Engineering LLC M MAELLC COM F 1 cae ie Interface layout When a new Modeler module is created the interface appears as shown below Note that a new set of menu entries has appeared between the two pipe bars These menus are grouped into the four element types electrical mechanical acoustical thermal and a miscellaneous menu The Miscellaneous menu contains the graph element which is required to show modeling results Ares Acoustic System Ares me4 3 muueieryy Fie New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous YOptions Window Help i lal ee Element Params Yariables Global Params element parameter selection menus selection tab bar parameter area icon model area lt scrollpos 0 0 fview L 0 R 264 5 T 0 B 186 FmaxCoord L 0 R 0 T 1000 B 1000 Copyright 2012 2013 McIntosh Applied Engineering LLC 4 Building a model To introduce the workings of
5. D You can manually route a connector by left clicking along a path between the two element nodes For example connect the voltage node to the speaker node by clicking twice to bring the connector above both elements ick a ys left click _ S Then finally click on the speaker terminal to complete the connection Ares will automatically align the last click point to be in line with the last node you click on Note that one section of a connector can be moved by moving the mouse over it and dragging Copyright 2012 2013 McIntosh Applied Engineering LLC A connector can be deleted by right clicking on it and selecting delete connector But let s not delete the connector we just created delete connector K select all Also once you start a connector you can cancel it by pressing the Esc escape key Another convenient way to delete a connector is to click on it close to an icon for editing and then just press the Esc escape key to cancel it Once a connector has been put in place it can be detatched from a node by clicking on the last line segment of that connector If you want to disconnect the connector from the terminal of the speaker you d left click on the line segment connected to the node as shown below This will detach the connector from the speaker but keep it connected to the voltage source element You can then re route the connector or simply press the Esc escape
6. The electrical acoustical transfer function element does not load the circuit that the left input node is connected to That is the input impedance of the input node 1s infinite Copyright 2012 2013 McIntosh Applied Engineering LLC 48 Q differential voltage amplifier Amplifies the voltage difference on the left nodes and produces a voltage on the right The input voltage nodes have infinite impedance If Vin is the voltage across the left input nodes and Vout is the is the current across the output nodes on the right then Vout G Vin G Amplifier gain Jd current amplifier Amplifies the current into the left nodes and produces a current out of the right nodes There is no voltage drop across the input terminals on the left If Iin is the current into the top left input node and Iout is the current out of the upper right node then Iout G tin G Amplifier gain 9 transconductance amplifier A transconductance amplifier is essentially a voltage controlled current source where the gain is amps volts or units of conductance The input voltage nodes have infinite impedance If Vin is the voltage across the left input nodes and Iout is the current out of the upper right node then Iout G Vin G Amplifier gain Copyright 2012 2013 McIntosh Applied Engineering LLC 49 Q 4 transresistance amplifier A transresistance amplifier is essentially a current controlled voltage s
7. Acoustex 075 Shape A Acoustex_075_A bin Acoustex 075 ShapeB Acoustex_075_B bin Acoustex 075 Shape C Acoustex_075_C bin Acoustex 075 Shape D Acoustex_075_D bin Acoustex 160 Shape A Acoustex_160_A bin Acoustex 160 ShapeB Acoustex_160_B bin Acoustex 160 Shape C Acoustex_160_C bin Acoustex 160 Shape D Acoustex_160_D bin Any new files will be downloaded to a subdirectory called acoustic_materials of the directory that Ares exe is being run from The contents of the Ares exe directory is shown below with the acoustic_materials di acoustic_materials _ Ares ARES LIC _ Ares ctg Ares exe E zw exe Copyright 2012 2013 McIntosh Applied Engineering LLC 38 The contents of the newly created acoustic_materials directory is shown below The new impedance data files appear as bin custom binary format files with the QOO_material_database txt file giving the master list of these files for Ares Itis recommended that you not make any changes to this directory If it becomes corrupted you can delete the acoustic_materials directory and recheck the internet for updates Ares will recreate the directory for you with all of the impedance data files from the internet database __ 000_material_database tet Acoustex_025_A bin Acoustex_025_B bin Acoustex_025 C bin Acoustex 025_D bin Acoustex_075_A bin Acoustex_075_B bin Acoustex_075_C bin Acoustex_075_D bin Acoustex 160_A bin Acoustex_160_B bin Acoustex 160_C bin Acoustex
8. This will accurately model the standing wave along the length of the volume L Total physical length of the port W Width of the port which should be greater than its height 1 e W gt H H Height of the port which should be smaller than its width 1 e H lt W R Resistance of the acoustic material placed at the right end of the port The units are MKS Rayls which is an area normalized flow impedance 1 MKS Rayls pressure drop Pa velocity through material m s Num The number of ports acting in parallel Vol The inner volume of the port S Cross section area of the port Ma Mass inertance of the port Copyright 2012 2013 McIntosh Applied Engineering LLC T1 A rectangular port whose height has a linear taper of Hleft on the left and Hright on the right See the description for regular slot port for more information Note that the right end always has the larger opening regardless of how the icon is rotated tapered rectangular port L Total physical length of the port Ares will calculate the appropriate end correction The length is in the direction of fluid flow W Width of the port which should generally be greater than its height 1 e W gt H Hleft Height of the port on the left which should be smaller than its width 1 e H lt W Hright Height of the port on the right which should be smaller than its width 1 e H lt W R Resistance of the acoustic material placed at the right end of the port The units
9. are MKS Rayls which is an area normalized flow impedance 1 MKS Rayls pressure drop Pa velocity through material m s Num The number of ports of dimensions acting in parallel Vol The inner volume of the port Sleft Cross section area of the port on the left Sright Cross section area of the port on the left radiating rectangular port Combines a rectangular port and a radiation element The result is the same as if a radiating element was connected to a rectangular port element Since most radiating holes or slots are driven by a port this element is meant to eliminate the task of creating two elements and matching their areas See the help for the two elements for more detail L Total physical length of the port W Width of the port which should be greater than its height 1 e W gt H H Height of the port which should be smaller than its width 1 e H lt W R Resistance of the acoustic material placed at the right end of the port where the radiation element is located The units are MKS Rayls which is an area normalized flow impedance 1 MKS Rayls pressure drop Pa velocity through material m s Rdist Radial distance that the radiated pressure will be calculated for Dbaff Diameter of the surface that the holes are radiating from Num The number of ports of dimensions L W H terminated with resistance R acting in parallel Vol The inner volume of the port S Cross section area of the port Ma Mass
10. button to delete the connector altogether This ability to move a connector is especially useful for graph connectors when you want to plot the data at different nodes When making a connector you may want to make sure that the last line segment has a significant length to make it easier to click on should you want to move the connector Copyright 2012 2013 McIntosh Applied Engineering LLC 3 Finish connecting the model as shown below To calculate the solution either press the CALC button in the tool bar or press the F5 key Ares Acoustic System Ares1 module 1 Modeler Ea File New Module Modules Electrical Mechanical Acoustical Thermal M OD W CALC Element Params Yariables Global Params press CALC or press F5 function key The calculation progress status will be displayed in the upper left corner of the icon model area In this case the model is so simple it will likely finish in a fraction of a second so the solution state will just flash up onto the screen For more complicated models or more frequency points than the default 200 the calculation will take longer If the solution is taking too long the Stop button to the right of the CALC button can be pressed to terminate the solution and fewer frequency points can be entered to speed up the solution For this simple model the number of frequency steps has been increased to 20000 so the progress could be captured This is shown below Note that the
11. from spectrum data valid on spectrum with units of V Pa Shift buffer data by dB value This feature will multiply the node data by the associated dB scaling factor and permanently change the data in the graph buffer This is especially useful when you ve imported measured data that needs to be properly scaled to better match the model data Note that since the impedance is a ratio of the pressure and velocity or voltage and current etc this dB scaling does not affect impedance data Copyright 2012 2013 McIntosh Applied Engineering LLC 36 Buffer weighting Multiple weighting types can be applied to the data presented for each buffer This large matrix of check boxes allows you to determine which weighting is to be applied to which buffer The plot using negative kinetic value is unique It changes the sign of the current or velocity or thermal flow values One of the results of this is that impedances will change sign Since all kinetic values are defined to be into the node this is useful when you want to plot the impedance looking out of a node Acoustic Material Database The impedance of an acoustical device such as a porous material membrane or even a complex shaped port is not always simply modeled from a few parameters In these cases it is sometimes easier to simply measure the impedance of such devices Ares Flow Impedance Module provides such impedance measurements For instance suppose you have an acoustic materia
12. gt Note that all of the curves look very similar but have an offset due to the sensitivity at each frequency To remove this sensitivity offset for each curve check the normalize to y option in the graph window to produce the following plot e s iterator Hz 100 400 1000 20 normalize to y oo at x ooo Copyright 2012 2013 McIntosh Applied Engineering LLC Graph window for element 8 0 r 100 Hz DI 4 26501 dB r 400 Hz DI 4 25856 dB r 1000 Hz DI 4 2441 dB r 2000 Hz DI 4 19892 dB r 5000 Hz DI 3 88914 dB z 2 3 D bo 3 o gt While not as attractive as a polar plot this does provide sufficient information to see the desired directivity for a microphone design Example 3 Rigid Rectangle Model of Microphone on Tablet This example shows how to use the rigid rectangle to predict the sound pressure on a tablet being used in a speaker phone application The tablet is modeled as an infinitely thin rigid rectangle The default 100mm wide by 200mm high size for the rectangle is used which roughly corresponds to a 7 inch tablet Create a new Modeler module from the New Module menu Pull the Acoustical menu down and select rigid rectangle about one third way down the menu and place it in the Ares window Create a graph element from the Miscellaneous menu and connect it to the first node on the rigid rectangle as shown below Copyrigh
13. Acoustical menu and selecting volume you can simple right click on an existing volume element and select duplicate volume element from the pop up menu duplicate volume element delete element Help for volume elements re rotate icon clockwise rotate icon counter clockwse rotate icon 180 degrees select all Copyright 2012 2013 McIntosh Applied Engineering LLC You can now drag the new volume element with the mouse and place it just below the speaker Then connect it to the speaker with a connector Pressing the F5 key or the CALC button will cause the model to be recomputed One advantage of using the right click feature to duplicate an element is that the new element will have the same parameter values You can delete an element by right clicking on it and selecting delete element from the pop up menu or you can select the element by left clicking on it and pressing the delete key If you want to delete many elements you can select multiple elements by holding down the shift key while left clicking on them or using a rubber band box to select multiple elements at once Once the multiple elements are selected press the delete key to delete them Rather than deleting the elements you can use the right click menu to copy the elements and then paste them into either the same model or a different model in a different Modeler instance Duplicating Models An extremely useful feature of Ares is the ability to du
14. SubCircuits When a model becomes too complicated or if you want to apply different fluid parameters to the acoustic elements a sub circuit can be used A subcircuit adds a new layer to a model Any number of subcircuits can be used The subcircuit model is shown below main circuit subcircuit subcircuit subcircuit etc tc To create a sub circuit select the subcircuit command from the Miscelleaneous menu and place the element in to the model sstical Thermal Miscellaneous Options Window Help graph naie Copyright 2012 2013 McIntosh Applied Engineering LLC 29 By default the subcircuit will be given the name Subcircuit as shown below File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneo D BWB cac Element Params Variables Global Params Subcircuit subcircuit 1 Subcircuit But it can be renamed by editing the field when the subcircuit element is selected as shown below ie Ares Acoustic System Ares1 module 1 Modeler id File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Option a DOD amp WH cac Element Params Variables Global Params 1 subcircuit porous filled volume porous filled volume To edit the subcircuit double click on the icon and add elements to the model The model below is asimple volume To connect nodes in the subcircuit
15. System Ares1 module 1 Modeler Sel File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help 8 X O a CALC Element Params Yariables Global Params 7 Vi fs z lt gt C La is i select all N lt i E scroll pos 0 0 fview L 0 R 264 5 T 0 B 186 FmaxCoord L 23 75 R 182 75 T 16 8 B 67 2 NUM Then left click on any of the selected icons and drag the icons around to a better position in the icon model area Ares Acoustic System Ares1 module 1 Modeler Fie New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help D o gt CALC Element Params Yariables Global Params G a lt scroll pos 0 0 fview L 0 R 264 5 T 0 B 186 FmaxCoord L 57 25 R 216 25 T 82 3 B 132 7 Next the icons have to be connected together To do this first click the mouse anywhere in the icon model area but not on an element This will deselect all of the elements Next move the mouse over the red node on the ground element 2 B It will turn yellow indicating that you re over that connector node Then left click on the now yellow node to begin the creation of a blue connector line Copyright 2012 2013 McIntosh Applied Engineering LLC i Next move the mouse over the lower node on the voltage source and left click again This connects the ground element to the lower voltage terminal of the voltage source
16. ament bur Lport 1 25 ament bu r amin 625 YY Voltage dB re RMS V it Global Parameters The Global Params tab displays a set of parameters that are common to the entire model and the fluid properties which are common to the circuit layer We ve already seen the iteration parameters but these parameters also include the frequency range as well as the air properties used for the elements Element Params Variables Global Params Frequency range for analysis Fmin 100 0 Hz X Fmax 10000 0 Hz F num points 200 7 4 logarithmic frequency distribution Iteration parameter range min iteration 50 0 max iteration 200 0 num 5 0 Fluid properties v compute fluid parameters for dry air Temperature 73 0 F s rho density 1 184 kgim 3 B bulk 1 4201e 005 Pa gamma ratio 1 4018 mu shear 1 8372e 005 Ns m 2 k thermal 0 0261 WimK cp heat 1006 0 JikgK T use porous material model pore diameter 0 2 mm x Copyright 2012 2013 McIntosh Applied Engineering LLC porosity 0 99 tortuosity 1 0 28 Fmin Fmax and num points determine the frequency range and the number of frequencies to be solved for The logarithmic frequency distribution check box determines how those points are to be distributed from Fmin to Fmax Either logarithmic if checked or linear not checked As previously discussed the teration parameter range determines how the parameters are iterated upo
17. current buffer angle 240 deg current buffer angle 250 deg current buffer angle 260 deg current buffer angle 270 deg current buffer angle 230 deg current buffer angle 290 deg current buffer angle 300 deg current buffer angle 310 deg current buffer angle 320 deg 1000 current buffer angle 330 deg hoo Frequency Hz current buffer angle 340 deg S 2 2 D bo z o gt Step 4 To see directivity click on the graph icon and change the following plotting options change type to linear check the vs iterator Hz option and enter the following frequencies to the right of the check box 100 400 1000 2000 5000 type vs iterator Hz THO 400 100020 normalize to y 0 atx O x axis range min y axis range min lt O Hide graph Set buffer line Advanced Options Now look at the graph again The response vs angle is now plotted as shown below Note that Ares automatically computes the directivity DI for the graph and displays the result in the legend Copyright 2012 2013 McIntosh Applied Engineering LLC Graph window for element 8 current buffer 100 Hz DI 4 26501 dB current buffer 400 Hz DI 4 25856 dB current buffer 1000 Hz DI 4 2441 dB current buffer 2000 Hz DI 4 19892 dB current buffer 5000 Hz DI 3 88914 dB gt 3 g a 4 D bo Z o
18. element to select it it s parameters will be displayed in the parameter area on the left side of the Ares window you ll need the Element Params tab selected The parameters for the speaker element are being displayed for the model below BBB Ares Acoustic System Ares modeler module 1 ARES module 1 Modeler fo aE File NewModule Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help E x D a EB caALC Element Params Ltesinhion Global Params description 32 ohm 103 uH 1 T m 15 6 mm 0 112 g 0 322 mech ohi 314 263 Hz 0 666606 11 683 ce PUNO OEE W qi s 4 4 4 4 param file classic parameters Thiele Small parameters Load speaker params from file ddi b Ready NUM The unique aspects of the parameter values are the units can be changed by using the drop down list box to the right of each parameter an equation can be entered for their value variable names can be used in the value equations o the parameter value can be iterated upon by pressing the l button to the right of each parameter An example of changing the units is shown below where the speaker parameter Re has had it s units changed from ohm to Kohm Note that Ares will automatically scale the numeric value to the appropriate units so 32 ohms becomes 0 032 Kohm Re 32 Le 103 0 032 Kohm E BL 1 Do 15 6 Mm 0 112 An exa
19. inertance of the port Copyright 2012 2013 McIntosh Applied Engineering LLC 78 exponential horn Models an exponential horn whose cross sectional area varies exponentially according to S x p D1 2 2 exp mx where m is the flair constant and x varies from 0 to L Note that the right side of the horn with the largest cross section area does not simulate any radiation conditions To model a radiating horn you must connect the right side to a radiation element Also note that by choosing the appropriate port parameters parabolic horns and conical horns can be modeled using the tapered rectangular port and tapered circular ports respectively L Length of the port Dleft Diameter of the left end of the port Dright Diameter of the right end of the port R Resistance of the acoustic material placed at the right end of the port The units are MKS Rayls which is an area normalized flow impedance 1 MKS Rayls pressure drop Pa velocity through material m s Num The number of horns in parallel m Flair constant of horn S x p DI 2 2 exp mx where x goes from 0 to L Fe Cutoff frequency no sound propagation below this frequency Copyright 2012 2013 McIntosh Applied Engineering LLC 79 ear simulator Represents the acoustical loading of artificial ear couplers The red node on the left side of the element icon represents the load of the ear and specifies the ear reference pressure ERP The blue sensing node o
20. into account standing waves along the port but the volume does not Copyright 2012 2013 McIntosh Applied Engineering LLC 73 By default the user specifies the height and diameter of a circular volume and displays the resulting volume The listbox in the element s parameters allows the user to alternatively specify the volume and calculate the height or diameter D The diameter of the volume used for end correction calculations Total volume will be pi H Do 2 2 H The height of the volume Vol The volume of the cylindrical volume D The radiation element is used to model the radiation of sound from a hole into an infinite air space Examples of this are radiation speaker radiating sound from a box into free space a port radiating sound into free space a leak radiating sound into free space When the diameter of the baffle is very large this element essentially realizes the classic baffled radiating source If the size of the baffle is set equal to the radiating hole diameter a non baffled radiating source solution will be used For finite baffle sizes a solution between the two will be used The blue node on the left side of the element is a listening node It represents the axial pressure at the specified distance from the radiating point This port cannot be loaded down but will always generate the same pressure no matter what elements you attach to it Each radiation element radiates into its own mathematical
21. pressure is computed from and is completely defined by the volume velocity out of right end of the circular port If another element is connected to the blue sensing node that element will not load down the rest of the model This is because a sensing node s pressure or voltage etc is only a function of the solution at the driving nodes In general you either connect a graph element or a summation element to the sensing nodes as it generally doesn t make sense to connect additional acoustical elements to sensing nodes Another important element that uses sensing nodes 1s the ear simulator Its sensing nodes display the DRP and free field corrected frequency responses This is discussed further in the elements section For instance suppose you want to model a bass reflex speaker design This would involve a speaker with a rear volume a radiating element on the front of the speaker and a radiating port attached to the rear volume To see the total pressure from the front and bass reflex port you would add the two pressures from radiation sensing nodes together This is shown below Note that it generally wouldn t make sense to add a volume element to the radiating element s sensing node But if you were to do so you d find that the volume element would not change the solution at the sensing node what so ever Also for a node the kinetic values such as current velocity volume velocity and thermal flow are always defined to be INTO t
22. s Do Diameter of a circle which has the same area of the acoustic material Note that only the area of the material that sound passes through 1s to be used in the area calculation Num The number of such Do areas through which sound passes through the material This can be used to indicate that the material covers an area of Num small holes of diameter Do resistor An acoustical resistor specifies the acoustical resistance between two nodes Acoustical resistance is the ratio of pressure drop over volume velocity Pa m 43 s acoustical ohms To compute end corrections the opening areas for the left and right nodes must be known Copyright 2012 2013 McIntosh Applied Engineering LLC 72 The element offers the ability to load impedance files from ARES_ZF or TXT files or from the online materials database The ARES_ZEF files are produced by the Flow Impedance Measurement Module The TXT files are text files with three space delimited columns Ist column frequency Hz 2nd column real part of impedance Acoustic Ohms Pa s m 3 3rd column imaginary part of Acoustic Ohms Pa s m 3 The online materials database has already been discussed in its own section Acoustical resistor differs from acoustical material in that the acoustical resistor uses acoustical ohms whereas the acoustical material uses MKS Rayls The fundamental internal unit of impedance that Ares uses is acoustical ohms pressure over volume veloci
23. same Ma value A port can also be used to model a volume driven at one end This will accurately model the standing wave along the length of the volume L Total physical length of the port Ares will calculate the appropriate end correction The length is in the direction of fluid flow Do Diameter of the port If the port is not circular this should represent an equivalent cross section area of the port R Resistance of the acoustic material placed at the right end of the port The units are MKS Rayls which is an area normalized flow impedance 1 MKS Rayls pressure drop Pa velocity through material m s Num The number of ports of dimensions L Do terminated with resistance R acting in parallel Vol The volume of the port S Cross section area of the port Ma Mass inertance of the port Copyright 2012 2013 McIntosh Applied Engineering LLC 75 al tapered circular port This is a circular port whose radius has a linear taper of Dleft on the left and Dright on the right See the description for a circular port for more information about ports Note that the right end always has the larger opening regardless of how the icon is rotated As with the circular port the listbox allow for the mass inertance Ma to be specified and the diameters or length computed to achieve the Ma value L Length of the port Dleft Diameter of the left end of the port Dright Diameter of the right end of the port R Resistance of
24. source element 1 is 94 dB which corresponds to 1 Pa However we re going to change it to 94 42 dB as shown below The reason for this is that the default sensitivity of the microphone is 42 dBV Pa A pressure value of 94 42 will result in O dBV out of the microphone assuming the port and volume structure do not affect the microphone response Element Params Yariables Global Params description P 4442 SL wy Finally we ve just used the default parameter values for the omni microphone element 4 By pressing the iteration button for the Lport variable as shown below we can compute a parametric set of frequency responses of the system for a variety of Lport values while still maintaining the Ltotal 10mm design constraint This is shown in the graph below Element Params Variables Global Params New variable Ltotal 10 22 Lins del Lport 1 ins del Hvol Ltotal Lport a Lins del Copyright 2012 2013 McIntosh Applied Engineering LLC 27 Note that since the low frequency sensitivity of the response is 0 dBV the levels at the high frequencies can be read as an effective increase in sensitivity due to the port volume resonance A 20 30 dB peak in the response is typically extremely undesirable so if this microphone is meant to operate over 3kHz this design would not work Graph window for element 6 current bur Lpon 0 275
25. the data in buffer A is the same as that in the Connector node buffer the two curves lie exactly on top of each other Pressure SPL 1000 Frequency Hz Now left click on the volume element so its parameters appear in the Element Params tab Change the volume s height H to 10 mm and press the CALC button Copyright 2012 2013 McIntosh Applied Engineering LLC 13 Ares Acoustic System Ares modeler module 1 ARES module 1 Modeler BE File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help k 5 CALC Stop E X Element Params Yariables Global Params description D 10 mm v GJ H flo mm vE Vol 0 785398 cc compute volume from height and diameter bi The graph now shows the results of the new calculation in blue and the A buffer with the original volume size in green It can clearly be seen that the effects of decreasing the rear volume reduced the low frequency response and shifted the main speaker resonance to just above 1 kHz Graph window for element 6 current buffer original buffer Pressure SPL 1000 Frequency Hz Duplicating deleting and copying elements If we wish to add an additional volume element between the speaker and the ear simulator rather than going to the
26. the two sensing points Copyright 2012 2013 McIntosh Applied Engineering LLC 68 J in sa Simulates a spherical wave propagating over two sensing points on an infinite plane surface The point source for the spherical waves are assumed to be on the plane surface The strength of the source is specified by entering the desired pressure at the left most node so a source strength and 2pi vs 4pi propagation issues are avoided This element is typically useful for directional microphone modeling specifically for bi directional microphones also referred to as closing talking or figure eight microphones The two connectors on the element icon represent the pressure at the two sensing points The output of the nodes has zero source impedance so no loading of the impinging wave is produced by connecting elements to the nodes For this assumption to be accurate it requires that the impedance into the circuit that the nodes drive is very large such as with small microphone sensing ports The element doesn t allow for the direction of the point source to be specified It is assumed that the directional properties of a microphone are to be applied to noise sources much farther away than the point source so plane wave sources should be used to determine directivity properties P Pressure of the impinging wave at the left most point R Radial distance from point source to the center of the two sensing points Dsep Distance separating the two sens
27. 0 70 60 ya 50 z 2 AO D current buffer H 25 mm Ss 30 current buffer H 43 75 mm current buffer H 62 5 mm 20 current buffer H 8 1 25 mm current buffer H 100 mm 10 speaker w o port 6 TT Tt Ares 100 1000 10000 Frequency Hz Copyright 2012 2013 McIntosh Applied Engineering LLC 89 Example 2 Microphone directivity The plane wave source in the Acoustical menu is used to create two pressure points that differ in phase according to a plane wave propagating in an infinite space The two connector nodes on the plane wave source can be thought of as two microphone ports on an infinite surface The parameters for this source include the angle and distance separating these two microphone ports This example shows how Ares can be used to model a directional microphone and compute its directivity Step 1 Create the following model using the plane wave source directional microphone circular ports and volumes from the Acoustical menu For this example the ports have diameters of 1mm and lengths of 2mm The volumes have diameters of 2 mm and heights of mm The default values for the directional microphone were used Step 2 Note that the default angle parameter for the plane wave source is 360 degrees We re going to change the iteration range to be from 0 to 100 By iterating on the 360 degree angle this will cause the plane wave source to vary its angle from 0 to 360 degrees E
28. 2 SP T oe Copyright 2012 2013 McIntosh Applied Engineering LLC 26 The design constraint is that the length of the port and the height of the volume must add to 10 mm To model this we re going to create three variables First select the Variables tab and click on New variable three times Change the name of the first variable to Ltotal and give it a value of 10 change the name of the second one to Lport and we ll start with a value of for it and then the third will be named Hvol and we ll set it to Ltotal Lport as shown below Element Params Variables Global Params New variable Ltotal 10 Lins del Lport 1 La Lins del Hyvol Ltotal Lport Lins del The port parameters element 2 in the model are assigned as shown below Note that for the length we ve used the variable Lport instead of a numeric value Element Params Yariables Global Params description L Lport mm Do 2 mm v ka R 0 MKS Ray L Num 1 sew Vol 0 00314159 cc S 3 14159 mm 2 n Ma 380 015 kgim 4 compute Ma from length and diameter a The volume parameters element 3 are assigned as shown below Note again that for the height we ve used the variable Hvol instead of a numeric value Element Params Yariables Global Params description D 5 mm 6 H Hvol mm gt 6 Wol 0 176715 cc compute volume from height and diameter The default value for the pressure
29. Ares Acoustical System Modeler Module User Manual Acoustical and Audio Measurement and Design Tools McIntosh Applied Engineering LLC MAE MAELLC COM info MAELLC COM support MAELLC COM Copyright 2012 2015 by McIntosh Applied Engineering LLC Eden Prairie MN USA Copyright 2012 2013 McIntosh Applied Engineering LLC Notice Ares is copyrighted and licensed by McIntosh Applied Engineering LLC MAE Ares and all of its hardware and software components are provided as is MAE makes no representations or watranties concerning the compatibility of Ares to the user s computer system or any potential damage caused to any computer peripherals digital storage systems or personal physical safety Further the accuracies of the measurement modeling and design components are not warrantied and should not be used as the sole source of evaluating an engineered system or component for commercial suitability or physical safety The user agrees not to distribute the Ares software to any non licensed third party attempt to disable the licensing system or reverse engineer the operation of the program or its hardware components Table of Contents INO MCCS tscatihtae techs eatin tee an ales etaeicataaeientiate enone team taht eo ealeemaa ahaa ieitin 2 T DEO COMON ee E S EON 2 Pocument Revision HISO sae a R A E e 3 ACOUSTIC Mod le Module sesers E E 4 VANES GE ACS VY OUI ece EN E E cea aallblaasie eoieacn ua saaae aselcneallesk 4 Bundi
30. Intosh Applied Engineering LLC 37 MAE provides another way to get impedance data files using an internet database established on the MAE web site You download files from the database which get stored to a local directory To gain access to the data files in the online database press the Select materials from database button The screen below will then appear The screen shows the local files which initially will be empty Select Acoustic Material Plotting options 12 MKS Rayls Ohms magnitude real amp imag 11 log x Clog y V autoscale graph unselect all select all T check internet for updates D OK Cancel Impedance MKS Rayls 09 08 0 Frequency Hz KMAY WAV MAVMAYV CODD D PPP PPPS manufacturer material name filename resistance MKS Rayls gt o 5 n u os ngo SSSTERRH RE EES Seb Seana se ks i Bye 2 Ank ae ee ee initially the file list ZEEE EER 3 will be empty Cesta fess 3 2g 834 z EG S 4 pF To check the internet for new files and populate your local directory press the check internet for updates button If new files are found they will be listed in a dialog box that will appear after the internet database is checked Ares New Files Loaded ES The following new materials have been loaded Acoustex 025 Shape A Acoustex_025_A bin Acoustex 025 Shape B Acoustex_025_B bin Acoustex 025 Shape C Acoustex_025_C bin Acoustex 025 Shape D Acoustex_025_D bin
31. MS levels can be plotted By default Ares assumes RMS drive units for all voltages and pressure sources Legend options The buffer letter can appear in the graph legend if desirable Also by default the legend can be dragged around You can fix its location or opt for it not to be drawn at all Metric to display in legend There are many metrics that can be displayed in the graph legend for each buffer Ares will do its best to make sense of the node data and generate the appropriate metric requested average level a power average of the frequency data 300 3000 Hz average level power average over the 300 to 3000 Hz data P50 weighted average level power average after a P50 speech weighing is applied P50 wghtd 300 3000Hz average level power average over 300 to 3000Hz data after a P50 speech weighing is applied Zwicker loudness Zwicker loudness computed from frequency response P50 weighted Zwicker loudness Zwicker loudness computed from P50 weighted frequency response data RLR narrow band 176 to 5490 Hz ITU RLR Receive Loudness Rating computed from spectrum data valid on spectrum with units of Pa V RLR wide band 88 to 9000 Hz Wideband ITU RLR Receive Loudness Rating computed from spectrum data valid on spectrum with units of Pa V SLR narrow band 176 to 5490 Hz ITU SLR Send Loudness Rating computed from spectrum data valid on spectrum with units of V Pa SLR wide band 88 to 9000 Hz Wideband ITU SLR Send Loudness Rating computed
32. OOO C normalize to y 0 atx D Pn CJT OOOOOOOOOOOOOOOOOOOOOOO0 x axis range min psophometric weighting JTINIOIOOOOOOOOOOOOOOOOOOOOO0 plot usingnegative JO OOOOOOOUOOOOOOOOOOOOOOOO0 y axis range min EEE C Hide graph Set buffer line Advanced Options Suppose you would like to see how the speaker output to the ear simulator changes as the rear volume element size is decreased The graph element uses buffers to hold the node data The buffer labeled Connector node holds the data for the node that the graph connector is connected to In this case it s the ear simulator node By pressing one of the Plotting buffer buttons A Z the Connector node data is copied to a buffer Copyright 2012 2013 McIntosh Applied Engineering LLC connector data stored in this Connector node buffer 4 he text areas to the right of he plotting buffers allow pressing the A button will Plotting buffers a ff sh ae escription of cause the connector data a A the data stored in the be copied to the A buffer buffer this text will appear E in the graph legend when the check boxes determine the data is plotted if that buffer is plotted in the graph element plotting window For this example press the A button and type original volume into the A buffer description and then check the A buffer box as shown below Connector node This causes a second graph to appear in the graph window but since
33. Stop tool bar button is enabled Ares modeler module 1 ARES module 1 Modeler i Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help P Stop Stop button na solution progress iables Global Params Frequency 411 652 Hz 6146 20000 lt Y alysis Solution Errors Occasionally you may find that the solver generates an error This is usually caused by an unrealizable solution For instance if you connect a 1V source to ground Ares won t be able to find a solution A more common problem is to have an unconnected element in the model For instance if we add another volume element but we don t connect it to the rest of the circuit the pressure in the volume will be undefined and an error will result If you want to create an element and one already exists in your model a convenient way to produce a new one is simply to right click on the existing element and select duplicate volume element from the pop up menu We ll do that for the speaker element Copyright 2012 2013 McIntosh Applied Engineering LLC ig undo delete C duplicate speaker element 2 delete element h G b Help For speaker elements 7 rotate icon clockwise Vv rotate icon counter clockwse rotate icon 180 degrees select all A big advantage of duplicating elements instead of creating new ones from the element menus is that the duplicated elements will have the same parameter values as the element you dupl
34. _160_D bin Once the local acoustic_materials directory is populated with data files they will appear in the acoustic material selection window as shown below Select Acoustic Material Plotting options MKS Rayls Ohms magnitude DO real amp imag C log x log y W autoscale graph Freg min max f Imped min max f _unselectall selectall check internet for updates ok cance HAY MAY MAY Impedance MES Rayls 5 S ww emper muni 6 S S Acoustex 025 Shape B Acoustex_025 Bin 25 Acoustex 025 Shape C Acoustex_025 Chin 25 Acowtex 025 Shape D Acowtex 025_D bin 25 Acoustex 075 Shape Acoustex_075 Chin 75 Acoustex 073 Shape D Acoustex_073_D bin 75 PIS urina um oze owd amp Guu p tan a lues Z UIU Bare 90 eam uodo um SS OLDY9 LY muB eon USS AE UPSLer S a peua Cud pi totg a plures y uo eBo qo BuppeaI ATAN AAAA 9Ep pou Acovstex 160 ShapeB Acoustex_160_B bin 160 rr ial Fl 4a os aa 1A The interface tries to pack a lot of information into a small space By clicking on an impedance file shown in yellow you can plot its impedance in the upper right corner of the window By double clicking on a file you can select it for importing into the element for simulation Multiple files can be selected and brought into the element You ll be able to either select one of these files to use in the element or iterate upon all of th
35. ailable in the modeler To get the most out of the modeler you will need to familiarize yourself with all of these options The options are extensive and will be discussed in their own sections later on For now we ll just make use of the plotting buffers to show how model results can be saved Copyright 2012 2013 McIntosh Applied Engineering LLC 11 Element Params Yariables Global Params Graph options description File Edit Connector node Quantity to plot Magnitude Format Legend options Metric to display in legend Plotting buffers magnitude O linear _ show buffer letter C average level g C real amp imaginary dB narrow band C 300 3000 Hz average level A Flphese Od full octave auto position P50 weigthed average level 0 Ae O dB 1 3rdl octave O fixed position _ PS0 wathd 300 3000 Hz average level F F leak toleranca PE O hide d Zwicker loudness g D P lie eae O C P50 weighted Zwicker loudness oe peak level CIRLR narrow band 176 to 4590 Hz Shift buffer data by dB value LJRLR wide band 88 to 9000 Hz O _ SLR narrow band 176 to 4590 Hz O 6 para a i _ SLR wide band 88 to 9000 Hz O H SZ Buffer weightings crrent A BG bE SE Gone ak EP MN er Sees Uv wax YZ quanmy pressure b Aweihttng A U I M W WEE W U e E E U U E E U E U e U E r U r i i type log x v Bweishtng ME E E E W E E W E W E E E E E E e e e E E E e e e O vs iterator Hz 0 Cweishtng QOOOOOOOOOOOOOOOOOOOOOO
36. and Vds gt Vgs Vth Ids KP 2 W L V gs Vth V gs Vth 1 lambda abs Vds Copyright 2012 2013 McIntosh Applied Engineering LLC a2 Once the DC operating point as been established the linear small signal model as shown below is applied for all non zero frequency operating points gale drain JOM CE 0 where gm 2 Ids V gs Vth ro 1 dambda abs Ids Cgs CGSO farads meter W meters Ids_ initial Initial value to assume for the current into the drain for the nonlinear iterative DC solver The closer the estimate is the faster the DC solver will converge Once a solution has been found for the circuit this value can be set to the Isd value to make the solver converge almost instantly Vth Threshold voltage KP Transconductance amplification factor for the small signal MOSFET This is to have units of A V 2 This parameter is equal to the factor U Cox seen in the MOSFET equations W Channel width L Channel length lambda Channel length modulation CGSO Gate source overlap capacitance per channel width Ids DC drain source current from DC solver Vgs DC gate to source voltage from DC solver Vds DC drain to source voltage from DC solver E Implements a P channel MOSFET to be used as a small signal amplifier These devices require a DC solution to establish their Ids bias point for the small signal analysis If the starting frequency for the analysis isn t 0 Hz the solver will automatically incl
37. ary dB narrow band E 300 3000 Hz average level phase dB full octave auto position 7 P50 weigthed average level F power dB 1 3rdl octave fixed position F P50 wgthd 300 3000 Hz average level hide EF Zwicker loudness leak toler oe ae RMS level F P50 weighted Zwicker loudness a peak level E RLR narrow band 176 to 4590 Hz Shift buffer data by dB value RLR wide band 88 to 9000 Hz SLR narrow band 176 to 4590 Hz aoe A y o apply SLR wide band 88 to 9000 Hz Buffer weightings current ABCDEFGHIJKLMNOPQRSTUVWX YZ A weighting F F i if Inn F Imm B weighing FF 0 0 0 0 0 0 0 o 0 A a o a a e a a a e a a a e e E i C weighting alala P PF a d alala al al F P50 weighting i psophometric weighting F 4 plot using negative kenetic value Quantity to plot By default only the magnitude of the node data is plotted however the node data is complex valued Selecting more plot types will cause them to appear in the graph window Leak tolerance plots the difference between Type 3 2 low leak and Type 1 and 3 2 high leak ear simulation results This requires data that has iterated using these ear simulators Time Copyright 2012 2013 McIntosh Applied Engineering LLC 35 response performs an FFT on the frequency data to produce a time domain data plot to show an impulse response Magnitude format Determines how the magnitude data will be plotted either as a linear quantity dB or in octave bands Also peak or R
38. as mechanical elements in series was actually mechanical elements in parallel with the confusion coming from where the spring was attached to the mass mass spring rigid wall force For the users experienced with mechanical impedance modeling this may at first be confusing To aid in this the mass element only has one node which indicates that the entire mass moves together and there is no velocity drop across a mass Note that the techniques and nuances of equivalent circuit modeling will not be taught in this user s manual MAE will be supporting them in other material and classes 44 Copyright 2012 2013 McIntosh Applied Engineering LLC Modeling Elements This section discusses each element in brief detail The more complicated elements such as the Graph element will be or have already been discussed in their own sections The text given below is duplicated in the program itself and can be displayed by right clicking on an element and selecting the help entry for that element For example the right click menu for the voltage source is shown below 1 fo t undo delete duplicate voltage source element delete element copy selections Help for voltage source elements rotate icon clockwise rotate icon counter clockwse rotate icon 180 degrees select all Selecting Help for voltage source elements brings up the following dialog displaying the help text help for vol
39. behave as a simple mass reactance However the port is implemented as a one dimensional standing wave tube with viscous and thermal effects accounted for so high frequency standing wave effects will be handled properly Also for very small diameters the viscous drag will introduce the proper lossy behavior for a small tube If a port isn t perfectly round the port s diameter Do should be specified so the cross section area of the actual port is the same as the circular port If the port is close to a circle the circular port should be used If the port is closer to a rectangle the rectangular port should be used The major difference between the circular and rectangular ports is how the viscous and thermal effects are accounted for A resistive damping material is also incorporated into the port on the right side of the element As the total resistance of the material is scaled according to the port s cross section area this is a more convenient way to deal with resistive cloths than using the damping material element By default the user specifies the length and diameter of the port and the element computes the volume surface area and mass inertance Ma from those When the port length is much shorter than a wavelength the port s behavior 1s well captured by its mass reactance Ma If the model is performing well with a specific Ma value you can use the list box to specify an Ma value and compute the length or diameter that provides the
40. ce is used to generate an AC voltage signal Whereas the standard voltage source specifies a voltage difference between its two nodes this element specifies a fixed voltage value at a single node The absolute voltage source is equivalent to a standard voltage source with the negative terminal connected to ground Note that this element will have a 0 V value at DC DC and AC voltages are specified independently to allow for bias voltages to be specified for semiconductor elements Vrms RMS volts at the elements single node t AC current source The current source is used to generate an AC current The current is typically a constant value but it can be made to have a complex and frequency dependant value by entering a value and using the f w and jw built in global variables To specify a complex frequency dependent current from a lookup table use a voltage source an electrical transfer function and transconductance amplifier elements Note that this element will have a 0 A value at DC DC Copyright 2012 2013 McIntosh Applied Engineering LLC 46 and AC voltages are specified independently to allow for bias voltages to be specified for semiconductor elements Irms RMS amps from the current source DC current source Provides a DC current This is useful for providing DC operating points for the nonlinear semiconductor devices such as diodes and mosfets Idc DC amps from the current source voltage amplifier Amplifie
41. e KLARES files are a text based file generated by the Klippel LPM Linear Parameter Measurement speaker parameterization tool The files look like this SourceDesc LPM Parameter Source description NumMaterial 0 Number of material Sd 0 049086999 m 2 Surface diameter of driver Fmax 1500 Hz Fmin 60 Hz SplitOctave 16 StimAmpEff 0 70710677 V StimAmpDBU 3 8021126 dB Mass nan Volume nan RShunt 0 Ohm UseShunt false FixedMmd nan kg R_E 5 3661113 Ohm L_E_0 0 00083420566 H L_2 0 0011805015 H R_2 5 4161461 Ohm K_LEACH 0 012161268 n_LEACH 0 74551348 Krm WRIGHT 0 00038905611 Ohm Erm_WRIGHT 1 0361816 Kxm_WRIGHT 0 0070239928 Ohm Exm_WRIGHT 0 8008 108 Cmes 0 0003233547 F Lees 0 042711235 H Res 41 143382 Ohm F_S 42 826194 Hz MMS 0 017091974 kg Rms 1 2847335 kg s C_MS_0 0 00080803296 m N Kms 1237 5733 N m b_0 7 2703702 N A LambdaS 0 028471029 Qtp 0 42173854 Q_ MS 3 5798804 Qes 0 46690466 Qts 0 41303474 Mmd 0 0048026456 kg Vas 0 27553837 m 3 Eta0 0 044564061 Lm 98 689848 dB rmseZ 0 040846359 rmseHx 0 017132032 BO_imported nan N A BICX 0 MMS_imported nan k
42. e data in the connector node buffer can be copied to other buffers by pressing the buffer buttons which are labeled A Z The graph element has many features that have already been discussed earlier in the manual i notes Allows you to enter text for documenting the model Copyright 2012 2013 McIntosh Applied Engineering LLC 84 Examples This section provides multiple examples of using Ares to model acoustical systems These are meant to be simple examples that can be built upon to model more complicated systems MAE also offers training classes to help further advance the user s skills Unless otherwise noted the default parameter values will be used Example 1 Bass Reflex Speakerphone A bass reflex speaker boots the low frequency output by adding a resonant port to the rear volume Before we add the resonant port we ll just model what the speaker does without it Build the model below using the default parameters The only parameter we ll change is the diameter of the radiating element 5 Change its Do parameter to E3_Do which means use the Do value from element 3 Note that you can only use parameters from elements with a lower index so element 5 can only use parameters from element s 1 4 e I Ares Acoustic System Ares1 module 1 Modeler bp S a e a i Sa O O n b File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help E X O s E CAE
43. e ear simulator The pressure shown when the graph is connected to this node is the equivalent diffuse field response that the ear simulator s ERP pressure represents for a HATS in a diffuse field Generally most audio equipment such Copyright 2012 2013 McIntosh Applied Engineering LLC SO as headphones and speakers are designed to have a flat diffuse field response However telephony equipment is generally designed so the ERP response fits inside of a particular mask The listbox chooses the type of ear simulator to use in the model The checkboxes select which ear simulators to iterate upon when the iteration button to the right of the listbox is pressed Four types of ear couplers are supported B amp K 4185 or ITU Type 1 The ITU Type 1 simulates a condition where there is a perfect seal between the phone and the ear B amp K 4195 low leak amp high leak or ITU Type 3 2 The ITU type 3 2 simulates a condition where there is a small and large leak between the phone and the ear Internally these are given the numeric type 4195 and 4195 1 respectively IEC 711 or ITU Type 2 The IEC 711 or ITU Type 2 looks like a large microphone cartridge but it actually contains acoustical chambers that give it an acoustical impedance that matches a part of the ear canal and ear drum Itis commonly used in HATS artificial ears B amp K 4128C or ITU Type 3 3 The ITU Type 3 3 is a rubberized ear pinna on a HATS that uses an IEC 711 to perfo
44. e model where the x axis is the Lport value Plotting vs the iterator value is especially useful for performing microphone directionality designs which will be demonstrated in the microphone example Vivs iterator Hz 100 500 1000 Graph window for element 6 current bur 100 Hz DI 36 6935 4B current bur 500 Hz DI 36 715 4B current bur 1000 Hz DI 36 7827 4B gt v A g fea 2 Ea G The Update graph button forces the graph to be redrawn with new settings Copyright 2012 2013 McIntosh Applied Engineering LLC 34 The Hide graph check box causes the graph window to be closed removing clutter from the desktop The Set buffer line button causes a dialog box to appear that allows you to set the line type weight and mark for each buffer curve Color is generated automatically Graph line type infomation Line type solid Line weight 1 The Advanced Options button causes the following dialog box to appear This has many useful features to help present the node data is a useful format Any changes to the entries in this dialog box are immediately applied to the graph You do not need to close the dialog box to see the effects Graph options File Edit Quantity to plot Magnitude format Legend options Metric to display in legend V magnitude linear show buffer letter average level real amp imagin
45. e of the port S Cross section area of the port Ma Mass inertance of the port Copyright 2012 2013 McIntosh Applied Engineering LLC 76 i rectangular port A port or vent that comprises a narrow rectangular constriction through which sound passes For low frequencies this will behave as a simple mass reactance However the port is implemented as a one dimensional standing wave tube with viscous and thermal effects accounted for so high frequency standing wave effects will be handled properly Also for very small dimensions the viscous drag will introduce the proper lossy behavior for a small tube The rectangular port is different from the circular port in that the port has a rectangular cross section to simulate a slot The significance of this is in how viscous drag is taken into account A resistive damping material is also incorporated into the port on the right side of the element As the total resistance of the material is scaled according to the port s cross sectional area this 1s a more convenient way to deal with resistive cloths than using the damping material element When the port length is much shorter than a wavelength the port s behavior is well captured by its mass reactance Ma If the model is performing well with a specific Ma value you can use the list box to specify an Ma value and compute the length or diameter that provides the same Ma value A port can also be used to model a volume driven at one end
46. e selected files just as you d iterate on a numeric parameter The file list can also be navigated by using the up down arrows and the spacebar for selecting Copyright 2012 2013 McIntosh Applied Engineering LLC 39 The upper left corner of the window allows the impedance data to be plotted in different units in magnitude or real and imaginary and log or linear scales The graph can also be either auto scaled or manually have the x y ranges entered The interface also allows for additional parameter fields to be displayed or hidden and sorts the list by those parameters wa AV MAY gt gt gt gt filb name resistance Ray i contract or hide field E ee NS PEET E ee Ee additional fields that Acousten 025 Bbin 25 pee 8 Acomtex_025_Chin 25 u E E o sort in ascending or ee ORTE can be expanded F BEE a ME descending order Acoustex_075_Abin 75 0 Be Acoustex_O75_B tin 75 DA Acoustex_O075_Cbin 75 as A eee PTR Th bo TS When the OK button is pressed the selected files will be imported into the element The listbox for the database files will now contain the selected files To use this impedance data for the element make sure the use database impedance data option is checked Select materials from database use database impedance data Acoustex 025 A bin Acoustex_075 A bin Acoustex_160 A bin Below we ve placed the acoustic material element in front of the microphone port and iterated
47. e velocity Produces a volume velocity through the terminals A positive value will produce a flow into bottom connector and out the top connector No interface area is specified so end corrections are not applied to the nodes of this element U Volume velocity produced by the source N 4 N plane wave source Simulates a plane wave propagating over two sensing points on an infinite plane surface The wave fronts are perpendicular to the plane surface and so no baffling occurs which would raise the pressure above that of the incident wave This element is typically used for directional microphone modeling with the two connectors on the element icon representing the pressure at the two sensing points For an angle of 0 degrees the wave moves from the left node to the right node At 90 degrees it is from top to bottom and the wave front excites both sensing nodes simultaneously At 180 degrees it is from right to left and at 270 degrees it s from bottom to top with the wave fronts again exciting both nodes simultaneously The output of the nodes has zero source impedance so no loading of the impinging wave is produced by connecting elements to the nodes For this assumption to be accurate it requires that the impedance into the circuit that the nodes drive is very large such as with small microphone sensing ports P Pressure of the impinging wave angle Angle at which the wave is approaching the two points Dsep Distance separating
48. ed in from the clipboard The format for the table is specified when data is read in The user will be presented with choosing between two or three columns and magnitude or complex formats Pout Pin H f Where Pout pressure out of the element on the right Pin is the pressure of the left input node H f is the complex transfer function loaded from the file and linearly interpolated at frequency f The acoustic transfer function element does not load the circuit that the left input node is connected to That is the input impedance of the input node is infinite One use for this element is when the input spectrum to a model is not flat For example if the response of a microphone to a P50 speech spectrum is desired a pressure source can be followed by a transfer function element with a lookup table that specifies a P50 spectrum loaded into it The magnitude response of the microphone will now be that of a typical P50 speech spectrum pressure Acoustic pressure at the node This specifies the exact pressure without any surface area interface so there is no end correction applied An equation can be entered in for the pressure including complex values such as jw However make sure that you re specifying a unit of Pa Copyright 2012 2013 McIntosh Applied Engineering LLC 67 and not dB if you re using complex values To shape the pressure spectrum an acoustic transfer function element is useful P Pressure at node volum
49. ent impedance The flow resistance is provided in units of Rayls which is normalized by the surface area Thus the area of the material that has sound passing through it must be specified This is done by specifying the diameter of a circle with the equivalent surface area The Num parameter allows you to specify multiple circular areas so that the total area will be Num times the individual circular area defined by Do Note that the round port and slotted port elements also have a damping material flow resistance term If a material is used that has a resistance or impedance that can be described by a simple DC flow resistance value or by equations with complex parts that can be entered into the parameter field then it is typically easier to use the resistance parameters in the port elements than to use a separate acoustic material element The element offers the ability to load impedance files from ARES_ZF or TXT files or from the online materials database The ARES_ZEF files are produced by the Flow Impedance Measurement Module The TXT files are text files with three space delimited columns Ist column frequency Hz 2nd column real part of impedance MKS Rayls Pa s m 3rd column imaginary part of MKS Rayls Pa s m The online materials database has already been discussed in its own section R Static flow resistance of the damping material in MKS Rayls 1 MKS Rayls pressure drop Pa velocity through material m
50. erence position MRP for a head and torso simulator HATS artificial mouth Xsrc the x coordinate of the point source Psrc Ysrc the y coordinate of the point source Psrc Zsrc the z coordinate of the point source Psrc this needs to be a positive value X1 Y1 the x y location of the first sensing port on the rectangle surface the front or back location is set by the drop down box below these values X2 Y2 etc repeat of X1 Y1 but for the other sending port locations Copyright 2012 2013 McIntosh Applied Engineering LLC 70 acoustical membrane The acoustical membrane element models the mass compliance damping M C R behavior of membranes or plates The M C R values can be entered directly or computed for the first mode from fundamental principles for a plate or membrane Plates differ from membranes by the source of the compliance or restoring spring force For plates the restoring force comes from the natural structural stiffness of bending the material For a membrane the restoring force comes from tension in the stretched material If the impedance of a membrane is measured using the Flow Impedance Module its impedance should be loaded into the acoustical resistance element M Num rho Fo Mechanical moving mass of the membrane Will be computed for the Ist mode if plate or membrane eqs option is selected Mechanical compliance of the membrane Will be computed for the Ist mode if plate or membrane eqs option is selected
51. field is a thermal node This is shown below for the electrical voltage mechanical force acoustical circular port and thermal mass elements However these elements don t mix node types OG 2g The elements below are hybrid elements that mix electrical mechanical and acoustical node types The first one is a BL coupler that converts an electrical signal to a mechanical force This simulates the behavior of a moving coil speaker s magnetic motor structure Note that the two electrical nodes are in a white field and the mechanical nodes are in a green field The last element on the right is an omni microphone It has an acoustical node that s in a blue field and two electrical nodes above and below the icon that are in a white field Again you can only connect electrical nodes to other electrical nodes mechanical nodes to other mechanical nodes etc When a circuit simulator such as SPICE is used to simulate mechanical acoustical lumped parameters an inductor is used not only for the electrical element but also for mechanical and acoustical masses The expert user has to keep track of what node 1s being used for each domain electrical mechanical etc and apply the correct conversion when graphing results Ares keeps track of this automatically One final note on nodes If you don t connect a node to anything a zero velocity or current will be assumed An exception to this is for mechanical elements which will assume a zer
52. first one on the front and the rest on the back Let s move the last two to 1 cm from the edge Set the Y3 and X4 parameters to the values shown below so the third point will be 1 cm from the top and the fourth point will be 1 cm from the right edge xJ 0 0 mm E Y3 90 0 mm os point 3 on rear shadowed side xd 40 0 mm jaa Yd 0 0 mm E point 4 on rear shadowed side Now run the solve by either pressing the CALC button or pressing F5 The solve will rapidly run through the low frequencies but take a longer and longer time as the frequency increases Copy all for positions to the A D graph buffers by connecting the graph to rigid rectangle s node 1 press the A button on the graph controls to copy the node data into that buffer Copyright 2012 2013 McIntosh Applied Engineering LLC 94 select the check box to the left of the A button type 1 into the comment for the A buffer Repeat this for node 2 3 and 4 so the graph element s parameters are as shown below Element Params Erara Global Params description Connector node Plotting buffers Al 1 2 3 D m Finally enter 50 for the x axis range min max field to force the graph to start at 50 Hz The graph element s graph will now appear as shown below Pressure 8 PL Note that the first point which is the only one on the front
53. free space and multiple radiating elements do not interact with each other To see the effect of multiple radiating sources you must use a Summation element to add their pressures together A radiating element is frequently attached to the end of a port For this reason there are hybrid circular and rectangular ports with a radiating element attached to them These behave identically to connecting a port and radiating element Using these hybrid radiating port elements can help simplify the model It is important to accurately estimate the value of Dbaff By default Dbaff is extremely large and so a baffled solution is realized But most devices will have a finite baffle size Leaving Dbaff extremely large will result in a prediction that s up to 6 dB higher than what will be measured The 6 dB value is the difference between radiating sound into a half space as opposed to a full space 1 e 2pi vs 4pi space respectively Rdist Radial distance that the radiated pressure will be calculated for Do Diameter of the Num holes from which the sound is radiating from If the holes are non circular this should represent the effective area of the individual holes Dbaff Effective baffle diameter of the surface that the holes are radiating from Copyright 2012 2013 McIntosh Applied Engineering LLC 74 om circular port A circular port or vent that comprises a narrow constriction through which sound passes For low frequencies this will
54. g Mms R_E_imported nan Ohm Re dTv 0 Copyright 2012 2013 McIntosh Applied Engineering LLC 62 TXT files are text files that contain lines that hold classic or Thiele Small parameters in MKS units The format is the parameter name a space and the MKS value for that parameter An example of the contents of such a file 1s Re 30 L Le 100e 6 R2 0 L2 0 BL 1 Do 16e 3 Mm 0 le 3 Cm 2 3e 3 Rm 0 3 Fo 300 Qms 0 7 Vas 12e 6 If a parameter isn t included in the TXT file it will be set to zero and reported in a dialog box after loading the parameters Radio buttons at the bottom of the parameter dialog box control which set of parameters are used for simulation Two standard Thiele Small representations are always available The advanced MAE speaker parameters will be available if they ve been loaded into the element Re DC voice coil resistance of the speaker Le Voice coil inductance R2 Electrical resistance due to eddy current losses Set to zero if unknown L2 Para inductance of voice coil The parallel combination of R2 and L2 appears in series with Re and Le Set to Zero if unknown BL BL product magnetic field coil length in the gap Do Diameter of the effective radiating surface area of the diaphragm Mm Moving mass of cone and attached air Cm Diaphragm compliance Rm Mechanical resistance of the diaphragm Fo Fundamental resonant frequency of cone Qms Q of the diaphragm s resonance Vas Equivalen
55. ge source and setting the voltage to zero Copyright 2012 2013 McIntosh Applied Engineering LLC 39 Mechanical Elements force Produces a mechanical force between the two nodes Since the mechanical admittance or mobility representation is used force is represented by a current and so both connectors must be connected to something in order to produce a force Typically the bottom node will be connected to a wall Not connecting one of the nodes means that there is no force on it If there s no force on one side of the element the element can t push the other node F Force produced between the two nodes velocity Provides a velocity between two nodes Since the mechanical admittance or mobility representation is used velocity is represented by a voltage For example connecting two 1 m s velocity sources in series will produce a total of 2 m s A wall element is usually connected to one of the nodes to produce a zero velocity reference point As with all other parameters the velocity can be defined to be complex and frequency dependant using the built in global variables j w and jw For example since displacement is the integral of velocity and since 1 jw is the frequency domain integration operator a velocity of 1 jw corresponds to a displacement source of 1 V Velocity across the two nodes mass Simulates a mechanical mass Since masses are incompressible the velocity of the entire mass is equal Also s
56. gs Vth ro 1 dambda abs Ids Cgs CGSO farads meter W meters Isd_initial Initial value to assume for the current into the source for the nonlinear iterative DC solver The closer the estimate is the faster the DC solver will converge Once a solution has been found for the circuit this value can be set to the Isd value to make the solver converge almost instantly Vth Threshold voltage This is a negative quantity for a P channel MOSFET KP Transconductance amplification factor for the small signal MOSFET This is to have units of A V 2 This parameter is equal to the factor U Cox seen in the MOSFET equations W Channel width L Channel length lambda Channel length modulation Copyright 2012 2013 McIntosh Applied Engineering LLC 54 CGSO Gate source overlap capacitance per channel width Isd DC source drain current from DC solver Vsg DC source to gate voltage from DC solver Vsd DC source to drain voltage from DC solver Di Sums the two electrical signals together The impedance into the terminals is infinite id Sums the three electrical signals together The impedance into the terminals is infinite dual input summer triple input summer 7 m quad input summer Sums the four electrical signals together The impedance into the terminals is infinite Vv ground The ground element is used to produce a zero electrical voltage This is equivalent to using an absolute volta
57. he node This is particularly important to understand when youre plotting impedance data If you want to see the impedance that the rear of the speaker is driving you can put the graph connector on the rear speaker node and then select plot using negative kinetic value from the graphs Advanced Options dialog box This will essentially change the impedance quantity from looking into the node to looking out of the node Node Domain Types For the most part the elements are one of four domain types electrical mechanical acoustical or thermal and you can only connect similar element types to the same type That is you cannot connect an electrical element to an acoustical element However some elements are actually hybrids One common example of this is the speaker element It has both electrical and acoustical nodes Copyright 2012 2013 McIntosh Applied Engineering LLC 19 electrical nodes ca Vr lt gt acoustical node In this case you can only connect the acoustical nodes to other acoustical nodes and likewise with the electrical nodes Ares will not let you connect an electrical node to an acoustical node acoustical node gt u The icons have been designed so the node s domain type is shown by the color of the field that the node appears in In general if the connection node is in a white field it s an electrical node a green field is a mechanical node a blue field is an acoustical node and a red
58. icated The elements from the menus will have default values which probably won t be appropriate for your model However we haven t gotten to how to change the elements parameters yet Once the speaker element is duplicated pressing F5 will generate a solution error because the new speaker element has too many undriven nodes and a unique solution couldn t be found 100 uency distribution arameters for dry air D F w 1385 kgim 3 v 054 Pa v 1183 674e 005 Nsim 2 v Error evaluating model Singular solution matrix for the top level circuit Singular solutions are sometimes caused by Forgetting to add a ground to an electrical circuit All electrical circuts must have their voltage referenced to ground at some point Note error text has been placed in clipboard Correct the model by right clicking on the new speaker and this time select delete element Then press F5 again to recalculate the model undo delete duplicate speaker element delete element copy selections h Help for speaker elements rotate icon clockwise rotate icon counter clockwse rotate icon 180 degrees select all Displaying Model Results Once the model solution has been calculated each of the nodes will contain solution information For electrical nodes this will be voltage and current for mechanical this will be force and velocity and for acoustical this will be pressure and volume velocity To plot these quantitie
59. ince an admittance or mobility model is used for the mechanical models the velocity is modeled as a voltage Since there can t be a velocity drop or voltage drop in the electrical domain across the mass there is no need for multiple nodes M mass AW spring Copyright 2012 2013 McIntosh Applied Engineering LLC 56 A mechanical spring The forces on each side of the spring are equal so if one side of the spring isn t connected to anything it won t affect the model K spring rate Mechanical damper or dashpot Dampers are a source of mechanical loss As with a spring the forces on each side of the damper are equal so if one side of the damper isn t connected to anything it won t affect the model Note While Ares uses a mechanical admittance or mobility model the damper s parameters takes units of mechanical ohms which is an impedance quantity A mechanical ohm is defined to be force over velocity or N m s R mechanical resistance of damper Copyright 2012 2013 McIntosh Applied Engineering LLC 57 Simulates a circular magnet motor structure for a moving coil loudspeaker It includes the electrical impedance of the coil as well as the mechanical impedance due to the mass of the coil BL coupler The element has two options Use magnetic motor model and Use M H demag curve for material When both of these options are disabled you enter the BL resistance inductance and coil mass directly into the eleme
60. ing points Copyright 2012 2013 McIntosh Applied Engineering LLC 69 fu hae rigid rectangle A rigid rectangle element simulates the presence of a thin rigid body in space that s being excited by a point source above the rectangle This largely simulates a talker using a cell phone or a tablet where the rectangle is the cell phone or tablet and the point source 1s the talker The element allows for multiple sensing points which simulate microphone ports The solution is only a numerical approximation and not an exact solution Keep this in mind when interpreting the results The rectangle is in the xy plane at z 0 The width is in the x direction and the height in the y direction with the center of the rectangle at x 0 y 0 The xy locations of the sensing ports are specified They can be either to be on the surface of the rigid rectangle either front or back surface where the front is the side where the point source is located rigid rectangular plate sensing point or port Z point source Being able to predict the microphone pressure on the front and back of a cell phone or tablet is useful in determining microphone locations Four sensing locations are presently supported width the width of the rigid rectangle in the x axis direction height the height of the rigid rectangle in the y axis direction Psrc the pressure of the point source as measured at a distance of 1 inch or 25 4mm This is the common mouth ref
61. ivity of wire material Common values are copper 1 7241e 008 ohm m aluminum 2 824e 008 ohm m Density of wire material Common values are copper 8890 kg m 3 aluminum 2700 kg m 3 Thickness of insulation on wire Two times this value is added to the gauge diameter to the total wire diameter Number of layers to wind the coil with More layers make the coil thicker but if the coil height is larger than the gap more layers will place more of the wire in the gap Copyright 2012 2013 McIntosh Applied Engineering LLC 59 WIRE_length Total length of wire used to achieve desired Re COIL_windings Number of windings per layer around the coil COIL_height Height of the coil If this is larger than the gap height BL will be lost COIL_diameter Diameter of the coil COIL thickness Thickness of the coil COIL_mass Mass of the wire in the coil mechanical acoustical transformer Couples the mechanical and acoustic domains by transforming a mechanical velocity into an acoustic volume velocity Since acoustic sources are almost always dipoles e g a front and back speaker diaphragm the acoustic side has two nodes where the volume velocity into the lower node equals the volume velocity out of the upper node If Ua is the acoustic volume velocity out of the acoustic node then Ua pi D 2 42 Vm where D is the diameter of the acoustic diaphragm being mechanically driven and Vm is the mechanical velocity D diameter
62. l that covers a speaker to keep out water and dust The effect of that material will be described in terms of its acoustical flow impedance it presents to the sound that comes from that speaker Ares has two elements that can load in acoustical impedance data and use it directly in their simulations These are the acoustic material and resistor elements whose icons are shown below O m The parameters for the acoustic material element are shown below The Load impedance data file button allows you to load impedance data into the modeler directly from a file Once the data has been loaded the use file impedance data check box will be enabled Once checked the R parameter representing the resistance of the material in MKS Rayls will be ignored and the frequency dependent impedance data from the file will be used in subsequent simulations This is a very useful means to use custom measured or computed impedance data directly in an Ares model Note the acoustic material element uses MKS Rayls impedance data while the resistor uses couse Ohms impedance data where Acoustic Ohms is pressure over volume velocity or Pa s m Element Params Variables Global Params description R 30 0 MKS Ray l Do 10 0 mm E Num 1 0 Select materials from database use database impedance data No materials selected ann use file impedance data Load impedance data file Copyright 2012 2013 Mc
63. le I Bass Reflex Speakerphone wiscasescanectousocaacswanecetaerocnsea E varus ecien 85 Example 2 Microphone diteCU WILY osre A eaenaiieeee aaa e aren ena eannameenees 90 Example 3 Rigid Rectangle Model of Microphone on Tablet cc cceseeesseeeeeeeeeeees 93 Copyright 2012 2013 McIntosh Applied Engineering LLC Document Revision History Version Date 1 00 October 2012 1 01 March 2015 1 02 April 2015 Comments Initial documentation release Separated module manuals Added electrical acoustical transfer function Added R2 and L2 to speaker element Added the following elements to the Modeler electrical acoustical transfer function differential voltage amplifier current amplifier and transressitance amplifier Added the ability to inverse transfer functions imported into the Modeler 1 03 July 2015 1 04 November 2015 Copyright 2012 2013 McIntosh Applied Engineering LLC Added porous material to fluid properties subcircuits and the ability to import Klippel KLARES speaker parameter files Added the following elements Knowles and Sonion receiver and omni microphone elements electrical to acoustical transfer function diode N and P channel MOSFETs DC voltage and current sources Also added a DC solver when a nonlinear electrical device is present in the model such as the diode and MOSFETs Modified ear simulator element to fix IEC711 correction and changed sensing node from freefield to diffuse field
64. lement Params Yariables Global Params description P 94 0 SPL vl C angle 360 0 deg mE Dsep 7 0 mm mC Select the Global Params tab and change the iteration parameters to min of 0 max of 100 and the number of iterations to 37 This will cause the angle to change by 10 degree steps reas Iteration parameter range min iteration 0 max iteration 100 0 num tf Copyright 2012 2013 McIntosh Applied Engineering LLC 90 Step 3 Press the iterate button for the plane wave source s angle parameter The results are shown in the following plot However it s difficult to see any directivity results from the microphone design Graph window for element 8 current buffer angle 0 deg current buffer angle 10 deg current buffer angle 20 deg current buffer angle 30 deg current buffer angle 40 deg current buffer angle 50 deg current buffer angle 60 deg current buffer angle 70 deg current buffer angle 80 deg current buffer angle 90 deg current buffer angle 100 deg current buffer angle 110 deg current buffer angle 120 deg current buffer angle 130 deg current buffer angle 140 deg current buffer angle 150 deg current buffer angle 160 deg current buffer angle 170 deg current buffer angle 120 deg current buffer angle 190 deg current buffer angle 200 deg current buffer angle 210 deg current buffer angle 220 deg current buffer angle 230 deg
65. lements sin sine radian argument cos cosine radian argument tan tangent radian argument asin arc sine returns radians acos arc cosine returns radians atan arc tangent returns radians atan2 arc tangent of y x returns radians db decibel same as 20 log10 abs x Copyright 2012 2013 McIntosh Applied Engineering LLC abs absolute value angle angle returns radians log log base e logl0O log base 10 exp exponent mod modulus con complex conjugate sqrt square root o comment Built in variables 1 sqrt 1 J sqrt 1 pi 3 14159265 f frequency Hz JW complex radian frequency j 2 pi f Iterating a Parameter Iterating a parameter means to run the model for a range of parameter values For instance if you iterate upon a port length the model will be automatically solved multiple times for a variety of port lengths Each node will then contain multiple solutions that will be plotted when a graph element is attached to a node Iteration results can be saved in a graph buffer just as a single model solution By default the range over which the iteration is performed is from 50 of the current value to 200 of the current value or from one half to times two Also by default 5 iterations will be performed However these ranges can be changed in the Global Params tab section For the model below we ll iterate upon the rear volume To iterate upon the volume directly and not the height or diameter
66. lt parameters realize a cardioid microphone The microphone is modeled as a front damped port volume structure a rear damped port volume structure with a membrane in between The membrane is characterized by a single resonance mass compliance damping structure front volume resistive material The SEN parameter converts the membrane motion to voltage front membrane rear ports ports An omni microphone can be realized by essentially closing off the rear ports by making them extremely small and or making the rear resistive cover resistance extremely large To drive the microphone assembly a plane wave or point source should be used For a bare microphone it is important to get the spacing between the two nodes in the plane wave or point source to be accurate Typically this will be the length plus the radius of the microphone Since the response is highly sensitive to this spacing it may be necessary to experiment with it when realizing a design Df Diameter of front microphone ports into front cavity Lf Length of front ports Rf Resistivity of the acoustic material covering front ports Num_f Number of front microphone ports Vt Volume of front microphone cavity Mm Mass of diaphragm Cm Mechanical compliance of diaphragm Rm Mechanical resistance of diaphragm Dm Moving diameter of diaphragm Vr Volume of rear microphone cavity Dr Diameter of rear microphone ports Lr Length of rear ports Copyright 2012 2013 McInt
67. lues for just the second point connect the graph element to node 2 and uncheck buffers A D for plotting as shown below Element Params Variables Global Params description Connector node F Plotting butters aji B 2 lc 8 D 4 E el The result should be the graph shown below Little effect at low frequencies with a lot of activity at the high frequencies Copyright 2012 2013 McIntosh Applied Engineering LLC 96 coment bude Y2 am cent bur Y2 11 1111 mn quent bur YN mn oent bur 2 33 3533 mn omen bur 2 44 4444 mm omen bur 2 55 5556 mm cent bur Y2 66 0667 mm ament buds Y2 T7_T77E mm cent bur YI EEEEES em omen bur Y2 100 mm Cross sections of these iteration curves can be made by selecting the vs iterator graph feature Enter frequencies of 1000 4000 and 8000 for this parameter Change the graph type from log x to linear and clear the x axis range min max entry as shown below quantity pressure vee vs iterator Hz 1000 4000 8000 normalize to y 0 at x 0 x axis range min y axis range min Update graph Hide graph Set buffer line Advanced Options The result is the graph below which shows the pressure across the back of the rectangle from the center at Y2 0 to the top at Y2 100mm for the three frequencies we entered Copyright 2012 2013 McInt
68. mple of using an equation is shown below where the speaker diameter Do is being computed from a radiating surface area of 200 mm Since the area A 1 Do 2 Do 2 sqrt A T This also shows how a variable can be used in the parameter list In this case the built in variable pi 1s being used to represent 3 14159265 Copyright 2012 2013 McIntosh Applied Engineering LLC 22 Re 0 032 Kohm Le 103 uH BL 1 T m Do 2 sqrt 200 pi mm Mm D It s important to understand that when the equation is evaluated the numeric value will assume the units specified to the right of the parameters value In this case 2 sqrt 200 p1 evaluated to 15 96 which will have units of mm Had the units for Do be set to m the Do would have a diameter of 15 96 meters DUU DUU 4 4 4 44 54 In general the syntax used for evaluating variables follows Matlab The following operators and functions are presently implemented If more functions are needed you can request they be added to the next version of Ares Operators range operator matrix element separator plus multiply m element by element multiply divide element by element multiply solve linear system A exponent r element by element exponent not equals not equal amp and lt less than lt less than or equal to gt greater than gt greater than or equal to transpose Hermitian end last element of an array Functions find returns an array of non zero e
69. n They operate from a fraction in percent of the current value to another fraction By default the range goes from 50 or one half the current parameter value to 200 twice the current parameter value with 5 steps The author has found this range to be the most useful for most cases An exception is for directional microphone modeling which will be discussed in the directional microphone example The fluid properties determine the properties of the air in the elements By default the parameters will be computed for dry air at 73 degrees F However by unchecking computer fluid parameters for dry air the fluid properties such as density modulus viscosity etc can be entered manually For instance for underwater acoustics the parameters for water can be entered However most users will not be changing the fluid properties There also is a porous material option which will simulate filling the ports and volumes with a porous material such as polyester fiberglass or open cell foams Porous materials are typically used to increase the effective volume behind a speaker by causing the air to behave isothermally There are videos on the MAE website that details this behavior http maellc com videos asp vid AM5 AM5 The fluid parameters are applied to all elements in the circuit level and by default will be applied to all subcircuit levels To apply different fluid parameters to elements those elements must be placed in a subcircuit
70. n ein aV6 6 ay leseno merece ume E cinerea ee Str frre preteen Gate EEE 5 01 FW 6 lw 0 0 a a A E A E E oe IRC re ve Re ee eT 9 Drsplayin o INIOUS RESUS csc tii netese es A enasin ieee een udmnasiniaea 10 Duplicating deleting and copying eleMeMNS cc eseeeesecceceeceeeeeeseeccceeceeeeseseseeeeseeeaeaeenees 14 D phcann o Mode esn aa 15 OPOS NE a E a a a E rer areene nre ere 18 Node typesnenin enir a N E 18 1S able mMmodelsecHoNS esras a a ai 21 Modi yine Ekmen Paramete Seene a 22 MMe eat Fat a E E can tation EN A A ne asada aera AE total mah E ance em gendered 24 YEE Tig F210 Cols ean eset erie ean Renee O eee ne A eee ne ee eee ee Oe emer 26 Global Paranieters vuunscadseunuees maton a a a a nalam meetin enact dis 28 SUDE NCUS srs tes acer e ed nacen sti nnnanaed nace etigannancies necenciia auoansed uaccecta annexed macanetomusauasbesameers 29 End Ge iaverG Hke ll ceerperee errr re renee nearer ee mtrrn er te Tree veer ree nay eres mere re er Tevet e erat eemnr rea ee mera creer Teree er errr ree 32 Graph Elem it renien ea a a E a clakenetaens 33 Acoustic Maternal Database eoirce ne E 37 Mechu ALIN CLS nno on a a e E E 42 Mod ePm i eaa a A neta gen tan at rr mre aere 45 ETUC AN Eleme IMS en a sd dic Sern EET 46 Mechanica Elemen Si etiasiattenhabedsaaal nan tawad ie iad snen Gavan N 56 ACOUSTICAL FVCINCINS ita cicirsc cz ssiesissietsocinoczs E a Ra 6l Thermal Elemen esasa E a E Analaahaanh as 83 Example Sscennnen a a a a 85 Examp
71. n the right side of the element icon represents the pressure that would be measured by the ear simulator s microphone assuming a simple scalar calibration provided by the ear simulator The input of these ear simulators are taken to be ERP The response of these ear simulators are not flat to a constant pressure at ERP however their response at 500 or 1000 Hz is generally taken as their scalar sensitivity The response at the other frequencies is measured and provided as a curve with the simulators as a correction function The ear simulator element uses a typical sensitivity function to convert the ERP pressure to a pressure measured by the ear simulator assuming a simple scalar sensitivity value So assume Perp pressure at ERP in dB SPL Vmic voltage measured by the microphone in dBV Sen scalar sensitivity of the microphone at 500 or 1000 Hz in dBV 1Pa Corr frequency dependent correction function Then Vmic Perp 94 Sen Corr Where 94 is the conversion from 1 dBPa to SPL It is common for acoustic measurement systems to apply a scalar sensitivity to a microphone response and report the SPL from the microphone When this is done for an ear simulator the pressure reported is Pmeas Vmic Sen 94 From the previous equation we see that this is Pmeas Perp Corr Pmeas is the pressure that the ear simulator provides when a graph element is connect to the right side node There is a third node on the lower left corner of th
72. nt If Use magnetic motor model is enabled you enter the magnetic and voice coil structural information and the element solves for BL resistance inductance and the coil mass using an internal magnetic circuit model The element also allows you to load a magnet M H demagnetization data curve into the element and use this to determine the magnetic operation point for the material When demagnetization data is loaded the Use M H demag curve for material option becomes available When it s selected the magnet operation point MAG _ Br MAG HMmax MAG _BHoper will be computed from the magnet and gap size information Note that in all options the diameter Do of the area that the coil acts upon is required This is used for end corrections and to convert from mechanical to acoustical properties Typically the BL coupler will be used to drive a membrane element The BL coupler diameter should be the same as the membrane s diameter To specify the H vs M demagnetization curve click on the Load H mu M demag curve data button A dialog box will appear that will allow you to select an ASCII file with the appropriate data The file is assumed to have a TXT extension The format of the file is two columns The first column specifies the applied H field in MKS units of A m The second column specifies the residual magnetization material uxM in MKS units of A m NOTE This data comes from the second quadrant of the material s hysteresis cur
73. o force This is because the mechanical domain is solved using an admittance model whereas the electrical and acoustical domains are solved using impedance models Copyright 2012 2013 McIntosh Applied Engineering LLC 20 Disabling model sections Occasionally you ll want to temporarily remove some sections of the model Perhaps you re experimenting with adding additional elements or you want to identify just how some of the elements are affecting the model response To disable such sections you need to remove the connectors from the elements in question from the main part of the model Consider the model below Suppose you want to see the effect of removing the volume element 7 and the radiating circular port 8 from the model You can do that by simply removing the connector from the volume element 7 to the speaker element as shown below So now the pressure and velocities for elements 7 and 8 will all be Zero However simply disconnecting elements and leaving them undriven will sometimes cause the solver to generate a singular solution error for the system When this happens you can avoid the singular solution by simply driving the disconnected elements with an appropriate element Below shows a pressure source element 9 being used to drive the disconnected elements which will avoid a singular solution error Copyright 2012 2013 McIntosh Applied Engineering LLC 21 Modifying Element Parameters When you click on an
74. of acoustic source mechanical transfer function Transforms the input velocity to the output velocity using a complex frequency dependent lookup table The lookup table is provided in the form of text columns and can be loaded from a file or pasted in from the clipboard The format for the table is specified when data is read in The user will be presented with choosing between two or three columns and magnitude or complex formats Vout Vin H f Where Vout velocity out of the element on the right Vin is the velocity of the left input node H f is the complex transfer function loaded from the file and linearly interpolated at frequency f Copyright 2012 2013 McIntosh Applied Engineering LLC 60 The mechanical transfer function element does not load the mechanical structure its input is attached to That is the input impedance of the input node is infinite o displacement controlled voltage source Converts a mechanical displacement into a voltage through a conversion constant This can be useful to model how a microphone converts the displacement of the diaphragm into a voltage This element does not load the mechanical circuit and so does not provide any feedback to the mechanical solution K Conversion constant used to convert displacement to voltage wall A wall represents a zero velocity condition A wall is typically used for a force element to push against Since for an admittance or mobility represen
75. of the rectangle has the highest pressure which roughly has a 6 dB increase at higher frequencies Points 2 3 and 4 have their pressures drop off at higher frequencies as the rectangle is shadowing those sensing points At low frequencies the curves are all approaching the same values which result from the wavelengths being so long that the rectangles size being too small to significantly effect the sound wave Note that the 3rd point light blue curve is curving down as the frequency Copyright 2012 2013 McIntosh Applied Engineering LLC 95 approaches 50 Hz This is an artifact of the approximate solution used and not physically meaningful The iteration feature can be used to show how the pressure changes across the back of the rectangle To do this we ll iterate across the y axis from the center of the rectangle at y 0 mm to the top at y 100mm First go to the Global Params tab and set the iteration parameters to those shown below Iteration parameter range min iteration 0 ag max iteration 100 0 ag num 10 0 Going from 0 to 100 will cause the parameter to go from zero 0 to its current value 100 Now select Element Params tab select the rigid rectangle element and change the X2 and Y2 parameters to 0 100mm respectively x2 0 0 mm gt Y2 100 mm mim point 2 on rear shadowed side 4 Now press the iterate button to the left of Y2 This will run the solve 11 times which will take a while To plot the va
76. ols and the problems they can solve heat source Provides a constant supply of heat into a thermal circuit For example if 3 amps are being dissipated into a 4 ohm resistor the total power is I42 R 3 42 4 36 watts W The amount of thermal power coming out of the source A fixed temperature This can simulate an infinite heatsink at the specified temperature where no matter how much heat goes into it the temperature never rises constant temperature T Temperature of the node k a thermal mass A thermal mass whose temperature rises and falls with the amount of heat energy it absorbs or gives off The thermal mass is a combination of the volume of the mass its density and heat capacity V Volume of the mass rho Density of the material h Heat capacity of the material AW thermal resistor A thermal resistance The heat flow through the material is resisted by the value entered A large value would be a thermal insulator a small value would allow the heat to readily flow across the element s nodes R Thermal resistance Copyright 2012 2013 McIntosh Applied Engineering LLC 83 Miscellaneous Elements graph The graph element is the only way to see the results from the model s simulation It plots the solution values at the node that the graph element is connected to The graph element can only be connected to one node at a time The node data is copied to the graph s connector node buffer Th
77. onics hearing aid speakers and microphones Cs Semi capacitance AW semi inductor A semi inductance has an impedance of sqrtGw Ls or 1 sqrt w 2 Ls which consists of a real and imaginary term Eddy current losses in a moving coil s pole piece can be effectively modeled by a semi inductance element in parallel with the coil s inductance element Ls Semi inductance gb A gyrator transforms current to voltage In this case the current left into the upper left terminal generates a voltage K Ileft across the terminals on the right and the current Iright into the upper right terminal generates a voltage K Iright across the terminals on the left That is gyrator Vright K lTleft Vieft K Inght K Gyrator transformation constant L J transformer An ideal transformer If N1 is the number of turns on the left and N2 is the number of turns on the right then the turns_ratio will be N2 N1 If I is the current into the left coil i e into the left dot and I2 is the coil into the right coil 1 e into the right dot then I1 2 N2 N1 Copyright 2012 2013 McIntosh Applied Engineering LLC 51 If V1 is the voltage across the left coil and V2 1s the coil across the right coil then VI V2 NI N2 The violet dots denote classical terminals of the transformer into which the current flows turns_ratio Turns ratio of transformer N2 N1 diode Implements a diode that performs DC signal rectification useful for pro
78. onnector node When the graph is connected to a model node the data from that node will be copied into the graph element s Connector node buffer For the model below the electrical data for the top microphone node will be copied into the graph element for plotting 4 To effectively use the Graph element it s important to understand the buffer scheme The main graph parameters are shown below The check box under the Connector node indicates that the data in the Connector node buffer is to be plotted The graph element contains multiple buffers that can each store model node solution data There are 26 buffers labeled A Z They are displayed in groups A I J R and S Z When one of the graph buffer buttons such as AJ B etc are pressed the data from the Connector node buffer will be copied to that buffer A Z Data in that buffer will be plotted in the graph window 1f the checkbox to the left of the buffer button is selected Descriptions for each buffer can be entered which will appear in the graph legend Element Params Y ariables Global Params description Connector node Plotting buffers press a button to copy A data into the buffer 8 LS Pai a select a check box to E plot the data in that buffer H Aa JL sR JC sz quantity voltage X type log x X vs iterator Hz 0 normalize to y 0 at x 0 x axis range min y axis range min Update graph _ Hide graph Set buffe
79. osh Applied Engineering LLC 65 Rr Resistivity of the acoustic material covering rear ports Num_r Number of rear microphone ports SEN Free field sensitivity of microphone Fsen Frequency that sensitivity is specified at Lmic Length from front of mic to rear of mic Dmic Diameter of microphone an lt fee Mas _ Knowles omni microphone Implements a omni directional microphone Knowles Electronics The models used are loaded from the file VendorComponentLibrary ARES_VLIB which should be located in the same directory as the Ares exe executable Simply select the desired device from the dropdown listbox that appears in the element s parameter list If the device you want isn t listed contact MAE and request that it be added The and terminals are the electrical outputs the connector on the other side of the icon is the acoustic input port Sonion omni microphone Implements a omni directional microphone the Sonion corporation The models used are loaded from the file VendorComponentLibrary ARES_VLIB which should be located in the same directory as the Ares exe executable Simply select the desired device from the dropdown listbox that appears in the element s parameter list If the device you want isn t listed contact MAE and request that it be added The and terminals are the electrical outputs the connector on the other side of the icon is the acoustic input port The Sonion microphone models require an external DC p
80. osh Applied Engineering LLC 97 E 2 ment budEr 1000 Hz DI 3 14266 dE ment bur 4000 Hz DI 5 55805 dB omen bur 2000 Hz DI 10 2994 dE There is little variation in the pressure across the back at 1 kHz more at 4 kHz and a great deal at 8 kHz showing that the shadowing increases with increasing frequency Copyright 2012 2013 McIntosh Applied Engineering LLC 98 For more information about Ares and acoustical measurement and modeling tools and services contact MAE at info MAELLC COM support MAELLC COM 678 234 5079 Or see us at MAELLC COM Copyright 2012 2013 McIntosh Applied Engineering LLC 99
81. ource where the gain is volts amps or units of resistance There is no voltage drop across the input nodes on the left If fin is the current into the top left input node and Vout is the voltage across the nodes on the right then Iout G Vin G Amplifier gain VVV resistor A classic electrical resistor The Load impedance data file button can be used to load a complex impedance lookup table into the element Pressing this button will cause a dialog box to appear that will allow you to browse to a file containing the data The format for a txt text file is in three columns Ist column frequency Hz 2nd column real part of the impedance electrical ohms 3rd column imaginary part of the impedance electrical ohms To use this impedance data instead of the resistance specified with R the use file impedance data must be checked If the use file impedance data option is disabled then there isn t any impedance data loaded into the element R Electrical resistance AP WW inductor A classic electrical inductor L Electrical inductance H capacitor A classic electrical capacitor C Electrical capacitance Copyright 2012 2013 McIntosh Applied Engineering LLC 50 E A semi capacitor A semi capacitance has an impedance of sqrt j w Cs Note that unlike a real capacitor the sign on the imaginary part is positive One use for a semi capacitor is for implementing discrete models of Knowles Electr
82. ower supply connected to the top PWR element node This external power supply MUST be provided It allows for various power supply voltages to be used which is useful for determining the current drain from the microphone device An example of connecting a Sonion omni microphone is shown below a simple pressure source is exciting the microphone and the output response is being graphed The DC voltage source is being used to power the microphone Copyright 2012 2013 McIntosh Applied Engineering LLC 66 Converts an acoustic particle displacement to a voltage This is useful for realizing discrete transducer components such as a condenser microphone The displacement is obtained by dividing the volume velocity by the surface area computed from Do and then integrating by multiplying by 14w displacement controlled voltage Note You must specify the area used to convert volume velocity to particle velocity through the Do parameter The area is not automatically taken from the nodes that this element attaches to Sen Sensitivity of the converter in Volts per displacement Do Diameter used to convert the acoustic flow to a displacement typically the diameter of a membrane that the element is connected to acoustical transfer function Transforms the input pressure to the output pressure using a complex frequency dependent lookup table The lookup table is provided in the form of text columns and can be loaded from a file or past
83. plicate modules This is extremely useful when performing a design and you want to try alternative parameter values or a different element arrangement Suppose we want to try and improve our earpiece design by adding a leak between the speaker and the ear but we don t want to modify the original model design because we re already fairly Copyright 2012 2013 McIntosh Applied Engineering LLC 15 happy with it We just want to see if we can improve upon it but we want to keep the original design intact By selecting Duplicate current module from the Modules menu an exact duplicate of the current module is created BBB Ares Acoustic System Ares modeler module 1 ARES module 1 Modeler o Df File New Module Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help E x D 4 m Duplicate current module L Delete current module Element Params Rename current module vV module1 Modeler module The list of module instances are displayed at the bottom of the Modules menu The new module instance will have the name of the original module instance with duplicate appended Since the original model just had the default name of module 1 the new module s name is module 1 duplicate Ares Acoustic System Ares modeler module 1 ARES module 1 duplicate Modele File New Module Electrical Mechanical Acoustical Therma Da D gt le Duplicate current module Delete cu
84. r how they affect the model Below the model is shown with both the indexes and description text displayed 1 15z12mm driver Node types There are two types of nodes driven and sensing Most of the nodes are driven nodes which appear as red squares on the icons An example of a driven node is the single node of a volume element This node is driven by the rest of the circuit and will load down the circuit Since the node loads the circuit changing the volume element s parameters will change the model s solution at all of the other nodes A sensing node appears as a blue square on the icons These nodes are not to be driven but are outputs that produce frequency dependent values computed from the element s parameters and or from the element s other nodes An example of a sensing node is the far right node on the radiation elements The radiating circular port is shown below The value of the sensing node on the right is determined by the red node on the left which is driving the radiating port The radiation part of the element predicts the pressure at a distance from the port assuming that the sound radiated from a baffled circular port The blue sensing node on the right represents this 18 Copyright 2012 2013 McIntosh Applied Engineering LLC radiated pressure If the blue node is connected to other acoustical elements those element will not change or load the value at the sensing node lt i The radiated
85. r line Advanced Options Copyright 2012 2013 McIntosh Applied Engineering LLC s N enter descriptions for the plotting buffers the descriptions will appear in the graph legend for that buffer data 33 Each node contains two different types of data that depends on the node type as indicated by the table below Node Type Quantities electrical voltage and current mechanical force and velocity acoustical pressure and volume velocity thermal temperature and heat flow The quantity list box indicates what quantity is plotted The graph element will perform useful conversions for appropriate data For instance you can not only plot the volume velocity for an acoustic node but you can also plot the particle velocity and displacement Particle velocity is the volume velocity divided by the cross section area associated with the node and displacement is the frequency domain integration 1 jw of the particle velocity When data from multiple node types are plotted simultaneously such as electrical and acoustical the units from the first buffer plotted will be used The type listbox controls whether the graph is plotted with log or linear scales The vs iterator Hz checkbox allows you to plot data vs an iterator value for specific frequencies This is only useful for buffers that contain iteration data An example of this 1s show below where the iteration data is plotted for 100 500 and 1000 Hz This is for the previous microphon
86. res admittance model equivalent representation mechanical system impedance model representation admittance model representation force voltage force current velocity current velocity voltage node equal force node equal velocity force rigid wall dashpot dashpot spring mass dashpot spring mass force ao 1 iu It is believed by the author that it s easier for a novice to learn how to build equivalent circuit representations of mechanical systems using an admittance model because the model looks much more like the mechanical system than an impedance model However building equivalent circuits for mechanical systems can be challenging for the un initiated For the experienced user who is used to impedance representations it can be challenging to change your thinking and generate admittance models The author has found that keeping in mind what nodes represent helps tremendously with building the model For an admittance representation connecting element nodes together means that all of the connected nodes share the same velocity and the sum of all of the forces into the nodes must equal zero So for the model below all of the nodes that are connected together have the same velocity where in electrical circuit terms the velocity is represented by the node voltage Copyright 2012 2013 McIntosh Applied Engineering LLC 42 velocity of all connected nodes are equal ee forces into all connected nodes m
87. rm more realistic listening measurements than are obtainable with the Type 1 or Type 3 2 simulators Unfortunately the acoustical load that a phone will experience when placed against such a rubberized ear depends on placement orientation the force that is exerted against the ear and the shape of the physical phone This makes it impossible to define an independent impedance into such an ear However the impedance into the ear was measured for different loading forces and is used by the simulator Copyright 2012 2013 McIntosh Applied Engineering LLC 81 Sums two acoustical signals together The impedance into the summation terminals 1s infinite Sums three acoustical signals together The impedance into the summation terminals is infinite dual input summer triple input summer quad input summer Sums four acoustical signals together The impedance into the summation terminals is infinite pressure release Forces a zero acoustic pressure condition at its node The terms pressure release comes from underwater acoustics where the water air boundary is considered to be a pressure release boundary due to the substantially reduced characteristic impedance of air as compared to water Copyright 2012 2013 McIntosh Applied Engineering LLC 82 Thermal Elements Ares presently offers very limited thermal modeling capabilities If more features are desired please contact MAE as we re constantly looking to broaden our to
88. rrent module Element Params Rename current module module 1 Modeler module Now select radiating rectangular port from the Acoustical menu and place the new element as shown below Make sure you connect the red connector on the new element to the front of the speaker This simulates a leak to the outside air Press F5 to solve the model The result is shown below Note that the main result is that the low frequencies are lost as they easily escape through the rectangular port due to its low impedance at low frequencies Copyright 2012 2013 McIntosh Applied Engineering LLC 16 Graph window for element 6 Ai y E v g Z Now that we ve modified the model we want to give this new model instance a name that will be meaningful later on By selecting Rename current module from the Modules menu the following dialog box will appear that will allow you to change the module instance s name Change the name to testing speaker ear leak and press OK Dialog mym Rename the module to something descriptive of of what the module is for or what data it contains testing speaker ear leak Now when the Modules menu is pulled down the name of the current module will be changed to a meaningful name kg Ares Acoustic System Ares modeler module 1 ARES module 1 duplicate Mode EJ Fie New Module Electrical Mechanical Acoustical Therm D iS lz Duplica
89. s a graph element must be created and connected to the node whose values you wish to display The graph element is in the Miscellaneous menu Place the graph element as shown below and connect to the artificial ear input node Copyright 2012 2013 McIntosh Applied Engineering LLC 10 When a graph element is used a new window is created It will appear somewhere on the desktop completely separate from the main Ares window Shown below the graph window is directly behind the main Ares window You ll need to position and size the Ares and graph widows to make them both visible and accessible as needed Update graph C Hide graph et butter tine Advanced Options n O 0 fvewL 0 Am S08 e0 B26 FrarCoord L56 S45 R 219 59 f 54 5 The graph window that was created 1s shown below By default Ares plots the pressure in SPL However there are many more graphing options Graph window for element 6 Pressure SPL 1000 Frequency Hz You can create as many graph elements as you like with each generating their own graph window This way you can see the solution at different nodes in the model By clicking on the graph icon and selecting the Element Params tab the graph options are displayed These are shown below on the left By pressing the Advanced Options button the dialog box on the right appears These constitute the graphing options av
90. s the input voltage by the specified gain constant K and places the result on the output The input node on the left has an infinite input impedance 1 e it doesn t load the circuit at all K Amplifier gain Negative and complex values are allowed r n An ideal linear operational amplifier The output is chosen to force the two inputs to be equal The input impedance into the nodes is infinite IIR filter Implements an ideal infinite impulse response filter Multiple space separated values can be entered for the Xtaps and Ytaps parameters If Ytaps is 1 then an FIR filter is realized If x n is the nth Xtaps value and y n is the nth Ytaps value x n is the nth input and a n 1s the nth output then a 1 y n b 1 x n b 2 x n 1 b nb 1 x n nb a 2 y n 1 a nat 1 y n na Fs The sample rate that the HR filter taps are evaluated at Xtaps A space separated array of X taps that operate on the input values Ytaps A space separated array of Y taps that operate on the output values Copyright 2012 2013 McIntosh Applied Engineering LLC 47 x electrical transfer function Transforms the input voltage to the output voltage using a complex frequency dependent lookup table The lookup table is provided in the form of text columns and can be loaded from a file or pasted in from the clipboard The format for the table is specified when data is read in The user will be presented with choosing between two or
91. t 2012 2013 McIntosh Applied Engineering LLC 93 r T zi Ares Acoustic System Ares1 module 1 Modeler Soe File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help ox a aoe tk CALC Element Params Yariables Global Params description width 100 0 mm eo height 200 0 mm mim Psrc 90 0 SPL ow Xsre 0 0 mm 6 Ysrc 0 0 mm ow Zsre 100 0 a E Jo x1 0 0 mm ed 30 v1 0 0 mm point 1 on front side AE x2 0 0 mm B Y2 0 0 mm point 2 on rear shadowed side v x3 0 0 mm v E Y3 0 0 mm gt point 3 on rear shadowed side X xd 0 0 mm F YA 0 0 mm mim point 4 on rear shadowed side X The rigid rectangle element doesn t require any additional elements to predict the sound pressure on the surface of the rectangle Before we run the solver let s make sure that the frequency range is from 50 to 10000 Hz Select the Global Params tab and set the Fmin Fmax and num points to those shown below Element Params Variables Global Params Frequency range for analysis Fmin 50 0 Hz Fmax 10000 0 Hz num points 200 logarithmic frequency distribution Reselect the Element Params tab so we can see the element parameters again By default the rigid rectangle element has a height and width the size of a 7 inch tablet The four sensing points are all at the origins 0 0 with the
92. t air volume that has same Cm diaphragm compliance param file file from which the speaker parameters were loaded Knowles speaker receiver Implements a balanced armature speaker from Knowles Electronics These devices are also known as receivers in the hearing aid community The models used are loaded from the file VendorComponentLibrary ARES_VLIB which should be located in the same directory as the Ares exe executable Simply select the desired device from the dropdown listbox that appears in Copyright 2012 2013 McIntosh Applied Engineering LLC 63 the element s parameter list If the device you want isn t listed contact MAE and request that it be added The and terminals are the electrical inputs the spout on the other side of the icon is the acoustic output port S w C Sonion speaker receiver Implements a balanced armature speaker from the Sonion corporation These devices are also known as receivers in the hearing aid community The models used are loaded from the file VendorComponentLibrary ARES_VLIB which should be located in the same directory as the Ares exe executable Simply select the desired device from the dropdown listbox that appears in the element s parameter list If the device you want isn t listed contact MAE and request that it be added The and terminals are the electrical inputs the spout on the other side of the icon is the acoustic output port omni microphone An omni non direc
93. tage source voltage source The electrical voltage source is used to generate an AC voltage signal The voltage is typically a constant value such as 1 0 2 5 etc However the voltage expression can be complex and frequency dependant using the f w and jw built in global variables To specify a frequency spectrum using frequency lookup table use the electrical transfer function element Vrms RMS volts to be generated across the two terminals Copyright 2012 2013 McIntosh Applied Engineering LLC 45 Electrical Elements AC voltage source The standard voltage source is used to generate an AC voltage signal The voltage is typically a constant value such as 1 0 2 5 etc However the voltage expression can be complex and frequency dependant using the f w and jw built in global variables To specify a frequency spectrum using frequency lookup table use the electrical transfer function element Note that this element will have a 0 V value at DC DC and AC voltages are specified independently to allow for bias voltages to be specified for semiconductor elements Vrms RMS volts to be generated across the two nodes DC voltage source A DC voltage primarily used to set bias points for semiconductor devices such as MOSFETS used in microphone amplifier models This will have O V at frequencies other than 0 Hz Vdc DC voltage from the source generated across the two nodes absolute AC voltage The absolute voltage sour
94. tation velocity is represented by a voltage this is would be an electrical ground in an electrical circuit simulator Acoustical Elements speaker A moving coil loud speaker The speaker has two electrical nodes and on the top of the icon and two acoustic nodes which represent the front and rear of the speaker The traditional set of parameters for a moving coil speaker is the Thiele Small TS parameters There isn t a single set of parameters that define TS parameters The speaker element currently supports two representations One uses mass compliance resistance The other uses resonant frequency Q equivalent air volume The Load speaker params from file button allows for speaker parameters to be loaded from a file Presently three types of files are supported ARES_SPK TXT and KLARES ARES_SPK files are custom binary files that can hold several types of speaker parameters in the same file including the TS parameters For the advanced MAE speaker parameters more dynamic behavior of the speaker is captured including internal volume and higher order modal effects Also the speaker may only have a Copyright 2012 2013 McIntosh Applied Engineering LLC 61 single acoustic port in which case only the front acoustic port the one on the right is used This is the case for most hearing aid speakers Also the advanced MAE speaker parameters can characterize any linear device including piezo or balanced armatur
95. te current module Delete current module Element Params Rename current module module 1 Modeler module testing speaker ear leak Modeler module While the above model and its modification was trivial as the user gains experience with Ares he she will be generating much more complicated models and designs The user will find this ability to duplicate models to create a design branch of their main design extremely useful Creating a duplicate model is useful even to test some of the model s parameter changes Make sure you keep this method of investigating different designs in mind as you use Ares Copyright 2012 2013 McIntosh Applied Engineering LLC 17 Options Menu The Options menu controls the text that s displayed above the elements Each element is given an index number starting at 1 These indexes make it easier to denote an element when describing the model By selecting Display element indexes by icon the element number will be displayed Options Window Help Display element indexes by icon aa Display element descriptions by icon Auto renumber element indexes Also note that the first parameter for every element is a description string Below are the first few parameters for the speaker element Element Params Yariables Global Params description 15x12mm driver Re 32 ohm Le 103 uH ow BL 1 T m od The description strings can add descriptive information about the elements o
96. the acoustic material placed at the right end of the port so the effective resistance will be scaled according to the area computed from Dright The units are MKS Rayls which is an area normalized flow impedance 1 MKS Rayls pressure drop Pa velocity through material m s Num The number of ports acting in parallel Sleft Cross section surface area of left port computed from Dleft Sright Cross section surface area of right port computed from Dright Ma Mass inertance of the port Combines a circular port and a radiation element The result is the same as if a radiating element was connected to a circular port element Since most radiating holes are driven by a port this element is meant to eliminate the task of creating two elements and matching their areas See the help for the two elements for more detail radiating circular port L Total physical length of the port Do Diameter of the port If the port is not circular this should represent the cross section area of the port R Resistance of the acoustic material placed at the right end of the port where the radiation element is located The units are MKS Rayls which is an area normalized flow impedance 1 MKS Rayls pressure drop Pa velocity through material m s Ro Radial distance that the radiated pressure will be calculated for Dbaff Diameter of the surface that the holes are radiating from Num The number of ports acting in parallel Vol The inner volum
97. the modeler we ll jump right in and build a model In the Electrical menu select a voltage source Mechanical Acoustical voltage source absolute voltage bl current source voltage amplifier l and drag the voltage source icon that s created to a position in the upper left corner of the icon model area of the Ares window Click the left mouse button to drop the icon Note that you can left click drag the icon again to move it to another position Ares Acoustic System Ares1 module 1 Modeler File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help i k CALC Element Params Yariables Global Params description rms 1 v Ready Do the same with the following icons Electrical ground Acoustical speaker Acoustical volume Acoustical ear simulator Try to create the model shown below Ares Acoustic System Ares1 module 1 Modeler File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options Window Help Dd o gt CALC Element Params Yariables Global Params lt scroll pos 0 0 fview L 0 R 264 5 T 0 B 186 FmaxCoord L 23 75 R 182 75 T 16 8 B 67 2 Copyright 2012 2013 McIntosh Applied Engineering LLC Note that you can move all of the elements by right clicking in the icon model area and then choosing select all from the pop up menu Ares Acoustic
98. the rear volume was iterated This indicates that the rear volume is not controlling or having any significant effect on this drop out The designer would know to look elsewhere to improve the response near this frequency To adjust the iteration range select the Global Params tab The iteration parameters are located at the bottom of the controls as shown below Element Params Variables Global Params Frequency range for analysis Fmin 100 0 Hz X Fmax 10000 0 Hz X num points 200 v logarithmi eration parameter range min iteration 50 0 max iteration 200 0 R 5 0 Fluid properties v compute fluid parameters for dry air Temperature 73 0 F rho density 1 164 kgim 3 B bulk 1 4201 e 005 Pa F gamma ratio 1 4018 mu shear 1 8372e 005 Ns m 2 k thermal 0 0261 WimK cp heat 1006 0 JikgK use porous material model pore diameter 0 2 mm 7 porosity 0 99 tortuosity 1 0 Variables Variables allow you to specify critical parameter values in one central location and to define mathematical relationships between them This allows for very useful parametric studies For instance suppose you have a microphone port design where the length of the port and the height of the volume in front of the speaker must add up to 10mm This is sketched below Lport Hvolume omni microphone acoustic pressure port volume port diameter 2 mm volume diameter 5 mm Ltotal 10 mm Lport Hvolume 4
99. three columns and magnitude or complex formats Vout Vin H f Where Vout voltage out of the element on the right Vin is the voltage of the left input node H f is the complex transfer function loaded from the file and linearly interpolated at frequency f The electrical transfer function element does not load the circuit that the left input node is connected to That is the input impedance of the input node is infinite One use for this element is when the input spectrum to a model is not flat For example if the response of the system to a P50 speech spectrum is desired a voltage source can be followed by a transfer function element with a lookup table that specifies a P50 spectrum loaded into it The magnitude response of the model will now be that for a typical P50 speech spectrum electrical acoustical transfer function Transforms the input voltage to a pressure using a complex frequency dependent lookup table The lookup table is provided in the form of text columns and can be loaded from a file or pasted in from the clipboard The format for the table 1s specified when data is read in The user will be presented with choosing between two or three columns and magnitude or complex formats Vout Vin H f Where Vout voltage out of the element on the right Vin is the voltage of the left input node H f is the complex transfer function loaded from the file and linearly interpolated at frequency f Units for H is Pa V
100. tion depends on how the sound interacts with the environment when it exits the port For the two common radiating conditions of baffled and unflanged the effective lengths are Leff L 0 85 a_ fora baffled port Leff L 0 6 a foran unflanged port where a baffled port is a port radiating from an infinite plane or wall and an unflanged port is the end of a tube without any wall structure around it like the end of an organ pipe or a flute For a long port with a small diameter the end correction is negligible However for a very short port or for a port that s just a hole in a thin wall the end correction can dominate its acoustical behavior So to accurately calculate the response of an acoustical model the end corrections associated with the acoustical element must be accounted for Ares uses a proprietary algorithm for computing a good estimate for the end correction for the acoustical elements This eliminates the need for the user to manually enter an end correction for each element and it eliminates errors associated with not using them at all which novice users are prone to do Copyright 2012 2013 McIntosh Applied Engineering LLC 32 Graph Element The graph element is the sole mechanism for getting access to the model results Each graph element creates a separate window on the desktop that displays the actual graph You are not limited to one graph you can create as many graphs as you like The graph element has one sensing c
101. tional microphone The microphone is modeled using a series of ports backed by a volume The pressure inside the volume is converted to a voltage that s placed across the top and bottom electrical terminals the top terminal being using a simple sensitivity parameter This element does not model an internal diaphragm The port volume structure will load the acoustic circuit but the electrical output of the microphone is ideal i e it has zero internal source impedance resistive material covering ports volume The SEN parameter converts pressure in volume to voltage ports Do Diameter of the port leading into the internal volume L Length of the port leading into the internal volume R Resistivity of the acoustic material covering front ports Num Number of ports leading into the internal volume V Internal volume size SEN Sensitivity of the microphone applied to internal volume pressure Copyright 2012 2013 McIntosh Applied Engineering LLC 64 directional microphone Models a two port pressure gradient directional condenser microphone using fundamental physical parameters By a judicious choice of the parameters it can be any type from the family of pressure gradient microphones cardioid typically called a uni directional microphone bi directional typically called close talking microphone or a figure 8 pattern or a super cardioid also referred to as a uni directional microphone The defau
102. to the upper circuit level a node element needs to be created by using the node for exposing subcircuit connections command from the Miscellaneous menu as shown below Fal Ares Acoustic System Ares1 module 1 Modeler we Ld File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options Subcircuits Window Help iki gt CALC graph notes Element Params Yariables Global Params subcircuit description D H 1 The node elements can then be given a name and connected to the subcircuts In the model below the node name is volume and it has been connected to the volume node a Ares Acoustic System Ares1 module 1 Modeler wae File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Opi OC B cac Element Params Yariables Global Params 2 volume node name volume node Copyright 2012 2013 McIntosh Applied Engineering LLC 30 To return to the upper circuit level you can either use the right click menu and select move up one subcircuit layer or use the Subcircuits menu and select the circuit level to move to ir Ares Acoustic System Ares1 module 1 Modeler kd 4 OC BWB cac Element Params Variables Global Params 2 volume node name volume node File New Module Modules Electrical Mechanical Acoustical Thermal Miscellaneous Options S
103. ty Because of this acoustical ohms values imported into the acoustical resistor element are treated as independent of area However resistance or impedance in units of MKS Rayls must be scaled by dividing it by the surface area of the material to achieve units of acoustical ohms So the impedance in acoustical ohms that you specify with R or import into the acoustical resistor element from an impedance file is what s directly applied to the model However the impedance specified or imported into the acoustical material element is always scaled by the effective area specified by the element s Do and Num parameters R Resistance or impedance of air flow through resistor Acoustical ohms pressure volume velocity Pa m43 s kg m 4 s Dleft Diameter of the equivalent area of the left node Dright Diameter of the equivalent area of the right node Num The number of resistors in parallel fie volume An ideal compliant air volume The compliance is only a function of the total volume of the element so any combination of diameter and height that achieves the same volume will have the same compliance However if the input area of the volume as defined by its diameter is smaller than any other element attached to it an end correction will be applied and a small mass reactance into the element will be realized An ideal volume differs from a circular port of the same diameter and length The circular port s impedance will take
104. ubcircuits Window Help delete selected elements copy selections select all move up one subcircuit layer Thermal Miscellaneous Options Subcircuits porous filled volume 2 volume node Window Help Main Model Once you return to the upper circuit layer the nodes that were created in the subcircuit will appear in the Subcircuit icon as a connection node with the name given in the subcircuit This node can be connected to the circuit and will appropriately load the circuit Copyright 2012 2013 McIntosh Applied Engineering LLC 31 End Corrections Acoustic ports store kinetic energy in the air velocity or momentum When the acoustic wave exits a port the wavefront opens up gradually One of the effects of this is that there 1s a significant amount of energy stored in the air velocity in the vicinity of the port 4 a Oo lt lt area of high velocity not just contained to the port but exists over a small volume outside of the port as the flow grows outward and the high velocity kinetic energy velocity diminishes The kinetic energy present just outside of the port is frequently referred to as an attached mass For a circular port this mass is directly proportional to its radius and is commonly added to the length of the port For a port of length L and radius a the effective length of the port is the physical length of the port plus an end correction The end correc
105. ude a 0 Hz DC solution as a part of the solver run Since the DC characteristics of a MOSFET device is nonlinear an iterative solution is required Typically this iterative solver will converge within a few dozen iterations however it may never converge If this occurs you ll need to stop the solver and adjust the circuit to encourage it to converge Providing a better guess for Isd_initial may be required MOSFET Pchan Copyright 2012 2013 McIntosh Applied Engineering LLC 53 Except for the threshold voltage Vth the DC current and voltages are referenced so they are positive quantities for a P channel MOSFET when the device is being used as an amplifier the DC current is into the source and out of drain so its referred to as Isd instead of the more common Ids value referred Note that Isd Ids Same with the Vsg and Vsd voltages Vsg Vgs and Vsd Vds The nonlinear DC model used for the P channel MOSFET 1s given below for cutoff mode Vgs lt Vth Ids 0 for linear mode Vgs gt Vth and Vds gt 0 and Vds lt Vgs Vth Ids KP W L V gs Vth Vds Vds Vds 2 1 lambda abs Vds for saturation mode Vgs lt Vth and Vds lt Q and Vds gt Vgs Vth Ids KP 2 W L V gs Vth V gs Vth 1 lambda abs Vds Once the DC operating point as been established the linear small signal model as shown below is applied for all non zero frequency operating points dram where em 2 Ids V
106. upon the impedance files that were imported producing the following graph Note that the effect of the material s different flow impedances generates an overall sensitivity shift Also the resonance behavior of the material produces a noticeable effect upon the response between 1 and 5 kHz The design challenge is to find materials that can produce a desired frequency response Without the ability to measure and model the behavior of these materials you re typically left with trying to minimize the effect of the material Being able to predict its effect allows you to use the different materials properties to enhance your design something which is very hard to do without Ares Copyright 2012 2013 McIntosh Applied Engineering LLC 40 S E 2 2 Copyright 2012 2013 McIntosh Applied Engineering LLC 4 Mechanical Modeling Ares uses an admittance or mobility model representation for mechanical modeling not an impedance model The reason for this is that the iconic representation of a mechanical system is largely the same as that used when drawing an admittance model But for impedance models parallel mechanical systems become series systems when electrical equivalents are used and series mechanical systems become parallel electrical equivalents This is shown below On the left is a simple mass spring damper mechanical system the middle is the electrical impedance model equivalent representation and on the right is the A
107. ust sum to zero Also the forces at all of the connected nodes must sum to zero where the force is a vector or directional quantity with a positive value always being defined to be into the node In electrical terms the force is represented by the node current While the mechanical model uses an admittance approach the graph element only displays impedances Z and not admittance Y where Z 1 Y Note that the graph element faithfully represents all of the quantities such as velocity displacement etc The force velocity values are not reversed as you d see if you plotted voltage current using a model with a standard electrical circuit simulator One may confuse the following model as being modeled by a mass and spring in series This however is not the case mass spring rigid wall force The reason is because a mass is considered to be incompressible it doesn t matter where you attach the spring to the mass The spring will have the same motion displacement or velocity no matter where you attach the spring to the mass Copyright 2012 2013 McIntosh Applied Engineering LLC 43 So this representation mass spring Tigid wall force mass spring rigid wall force Is the same as this mass spring rigid wall force Which is the same as this SERRE mass force Which is the same as this 7 spring rigid wall Which in Ares is represented by this model So a model which was initially drawn
108. ve and so the H values must be negative BL Magnetic field in gap times wire length in gap Do Diameter of area that force is distributed over Re DC resistance of coil Le Inductance of coil Copyright 2012 2013 McIntosh Applied Engineering LLC 58 MAG ID MAG OD MAG thickness MAG Br MAG _HM file MAG _ BHmax MAG_BHoperate GAP_ID GAP_OD GAP_height GAP_B motor_efficiency WIRE_gauge WIRE_ resistivity WIRE_ density WIRE insulation WIRE_layers Inside diameter of magnet 0 if plug magnet Outside diameter of magnet Thickness of magnet Magnet remanence Used if demagnetization file isn t specified Also referred to as residual induction File from which demagnetization curve was loaded from The maximum energy product possible from the magnetic material The actual operating energy product from the magnetic material Magnet prices are typically determined by the volume of the material The material is being used most efficiently on a volume basis if the BH operating point is at or close to its maximum value Inside diameter of the gap Outside diameter of the gap Height of the gap Magnetic field in the gap Relative efficiency of the motor structure Due to flux leakage not all of the magnetic field will pass through the gap This represents the percentage that does Typically this is evaluated with an FEA magnetic model Gauge of the wire using the Brown amp Sharpe scale Bulk resist
109. viding biasing for other semiconductor devices such as a mosfet being used in an amplifier circuit The only effect that the diode has on the AC analysis is the small signal resistance rd When the diode is forward biased this resistance is rd n Vt Id where Vt 26mV When the diode is reversed bias rd is infinite Is saturation current or scale current n ideality factor Id forward bias DC current through diode Vd forward bias DC voltage across diode D IK s MOSFET Nchan Implements an N channel MOSFET to be used as a small signal amplifier These devices require a DC solution to establish their Ids bias point for the small signal analysis If the starting frequency for the analysis isn t 0 Hz the solver will automatically include a 0 Hz DC solution as a part of the solver run Since the DC characteristics of a MOSFET device 1s nonlinear an iterative solution is required Typically this iterative solver will converge within a few dozen iterations however it may never converge If this occurs you ll need to stop the solver and adjust the circuit to encourage it to converge Providing a better guess for Isd_initial may be required The nonlinear DC model used for the N channel MOSFET is given below for cutoff mode Vgs lt Vth Ids 0 for linear mode Vgs gt Vth and Vds gt 0 and Vds lt Vgs Vth Ids KP W L V gs Vth Vds Vds Vds 2 1 lambda abs Vds for saturation mode Ves gt Vth and Vds gt 0Q
110. we ll change the calculation option to compute height from diameter and volume as shown with the red oval Next press the iteration button s to the right of the Vol parameter as shown with the green oval Copyright 2012 2013 McIntosh Applied Engineering LLC 24 l m CALC Stop o Element Params Y ariables Global Params description 10 10 0 785398 a ompute height from diameter and volume _ gt SL The result of pressing the iteration button for the Vol parameter results in the solution shown in the graph below Note that the actual volume value used for each curve is shown in the legend The result is that the low frequency output drops as the volume is decreased cument bur Vol 0 392699 cc cument bur Vol 0 687223 cc mmen bur Vol 0 981748 ec ment bur Vol 127627 ec men buds Vol 1 5708 ec Pt 2 Parameter iteration is a good way to optimize a design For instance the above graph shows that volumes much larger than 1 cc start to have diminishing returns on increasing the low frequency output Copyright 2012 2013 McIntosh Applied Engineering LLC 25 Parameter iteration is also a good means of determining what elements are controlling the response especially around resonances or dropouts For instance the above model has a significant dropout at around 5 5kHz but the response at that frequency didn t change at all when

Manual for the Ares Modeler Module

Contents

Download Pdf Manuals

Related Search

Related Contents