dbx Pro fessional Products TV Cables AFS 224 User's Manual
Contents
1. AFS 224 User Manual db Analog Inputs Number of Inputs Connectors Type Impedance Max input line level CMRR Analog Outputs Number of Outputs Connectors Type Impedance Max Output Level A D Performance Type Dynamic Range Type IV dynamic range A D Conversion D A Performance Dynamic Range D A Conversion System Performance Sample Rate Dynamic Range THD N Frequency Response Interchannel Crosstalk Crosstalk input to output Operating Voltage Power Consumption Safety Agency Approvals 2 Female XLR and 1 4 TRS Electronically balanced unbalanced RF filtered Balanced 50kQ Unbalanced 25kQ 20dBu gt 40dB typically gt 55dB 1kHz 2 Male XLR and 1 4 TRS Electronically balanced unbalanced RF filtered Balanced gt 120 unbalanced gt 600 20dBu dbx IV conversion system gt 113 dB A weighted gt 110 dB unweighted 22kHz BW gt 119 dB A weighted 22kHz BW gt 117 dB unweighted 22kHz BW 24 bit 112 dB A weighted 109dB unweighted 24 bit 48kHz gt 109dB A weighted gt 106 dB unweighted 22kHz BW 0 003 typical at 4dBu 1kHz 20Hz 20kHz 0 5dB gt 80dB typical gt 80dB typical 100 50 60Hz 120VAC 60Hz and 230VAC 50 60Hz 9 Watts UL 6500 IEC 60065 EN 55013 E 60065 dbx PROFESSIONAL PRODUCTS AFS 224 User Manual 12 dbx PROFESSIONAL PRODUCTS Harman International Company2. DO NOT USE THIS APPARATUS NEAR WATER CLEAN ONLY WITH A DRY CLOTH DO NOT BLOCK ANY OF THE VENTILATION OPENINGS INSTALL IN ACCORDANCE WITH THE MANUFACTURER S INSTRUCTIONS DO INSTALL NEAR ANY HEAT SOURCES SUCH AS RADIATORS HEAT REGISTERS STOVES OR OTHER APPARATUS INCLUDING AMPLIFIERS THAT PRODUCE HEAT ONLY USE ATTACHMENTS ACCESSORIES SPECIFIED BY THE MANUFACTURER UNPLUG THIS APPARATUS DURING LIGHTNING STORMS OR WHEN UNUSED FOR LONG PERIODS OF TIME Do not defeat the safety purpose of the polarized or grounding type plug polar ized plug has two blades with one wider than the other A grounding type plug has two blades and third grounding prong The wide blade or third prong pro vided for your safety If the provided plug does not fit your outlet consult an trician for replacement of the obsolete outlet Protect the power cord from being walked on or pinched particularly at plugs con venience receptacles and the point where they exit from the apparatus Use only with the cart stand tripod bracket or table specified by the manufacture or sold with the apparatus When a cart is used use caution when moving the cart apparatus combination to avoid injury from tip over Refer all servicing to to qualified service personnel Servicing is required when the apparatus has heen damaged any way such as power supply cord or plug is damaged
3. x PROFESSIONAL PRODUCTS AFS 224 Dual Channel Advanced Feedback Suppression Processor ee a omen Se 2 IMPORTANT SAFETY INSTRUCTIONS CAUTION RISK OF ELECTRIC SHOCK ATTENTION risque ELECTRIQUE NE PAS OUVRIR WARNING REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE The symbols shown above are internationally accepted symbols that warn of potential hazards with electrical products The lightning flash with arrowpoint in an equi lateral triangle means that there are dangerous voltages present within the unit The exclamation point in an equi lateral triangle indicates that it is necessary for the user to refer to the owner s manual These symbols warn that there are no user serviceable parts inside the unit Do not open the unit Do not attempt to service the unit yourself Refer all servicing to qualified personnel Opening the chassis for any reason will void the manufacturer s warranty Do not get the unit wet If liquid is spilled on the unit shut it off immediately and take it to a dealer for service Disconnect the unit during storms to prevent damage SAFETY INSTRUCTIONS NOTICE FOR CUSTOMERS IF YOUR UNIT IS EQUIPPED WITH A POWER CORD WARNING THIS APPLIANCE MUST BE EARTHED The cores in the mains lead are coloured in ac
4. 8760 South Sandy Pkwy Sandy Utah 84070 Phone 801 568 7660 Fax 801 568 7662 Questions or comments E mail us at customer dbxpro com or visit our World Wide Web home page at www dbxpro com 18 6398 A
5. Ob o 20 20 996 Ce EL 1 2 3 4 5 6 7 8 OutputA Output B voc dbx PROFESSIONAL PRODUCTS AFS 224 User Manual 8 Application 3 Insert the Subgroups of a Mixer This setup is ideal for applications that require feedback suppression on certain instruments such as microphones while keeping instrument that desire feedback such as guitars separat ed This application provides the user with dual channels of 24 filter suppression per stereo channel of the mixing console subgroup I Connect the stereo output inserts of the mixer to the inputs of the AFS 224 2 Connect the outputs of the AFS 224 to the insert returns of the console 3 Making sure that all outputs are muted apply power to the mixer and amplifiers For maximum performance and proper operation the input signal to the dbx 224 must cause the 0 dBu LED to light fairly consistently and the 10 dBu LED to light occasionally Be sure to check the mixer s manual for the nominal operating point for the insert jacks and then select the 4dBu or 10dBV switch on the back of the 224 accordingly Subgroup Input Channel AFS 224 Subgroup Input Channel 2 AFS 224 Microphone In Insert Returns 0 3 2 SWT BAS Output Output B 9
6. liquid has been spilled or objects have fallen into the apparatus the ratus has heen exposed to rain or moisture does not operate normally or has been dropped POWER ON OFF SWITCH For products provided with a power switch the power switch DOES NOT break the connection from the mains MAINS DISCONNECT The plug shall remain readily operable For rack mount or installation where plug is not accessible an all pole mains switch with a contact separation of at least 8 mm in each pole shall be incorporated into the electrical installation of the rack or building FOR UNITS EQUIPPED WITH EXTERNALLY ACCESSIBLE FUSE RECEPTACLE Replace fuse with same type and rating only MULTIPLE INPUT VOLTAGE This equipment may require the use of a different line cord attachment plug or both depending on the available power source at instal lation Connect this equipment only to the power source indicated on the equipment rear panel To reduce the risk of fire or electric shock refer servicing to qualified service personnel or equivalent This Equipment is intended for rack mount use only IMPORTANT SAFETY INSTRUCTIONS ELECTROMAGNETIC COMPATIBILITY This unit conforms to the Product Specifications noted on the Declaration of Conformity Operation is subject to the following two conditions e this device may not cause harmful interference and this device must accept any interfer ence received including interf
7. be used during a performance The AFS 224 can be put into Live Mode by pressing the lt MODE gt button until it lights red in Live Mode if feedback occurs fil ter will be set at the feedback frequency If there are additional occurrences of feedback addi tional notch filters will be set until all the Live Filters are used If new frequencies begin to fee back and no more Live Filters are available the AFS algorithm will take the first Live Filter set and move it to the new feedback frequency The AFS 224 will continue to round robin through the Live Filters as new feedback is detected AFS 224 User Manual dbx PROFESSIONAL PRODUCTS Using Live Filter Lift Live Filter Lift provides maximum sonic integrity by removing unnecessary feedback filters The Live Filter Lift function provides a timer for each of the Live Filters This timer length can be adjusted by pressing the lt LIVE FILTER LIFT gt button and can be switched between off 1 minute 10 minutes or 60 minutes The filter lift default time is 10 minutes from the facto ry If Live Filter Lift is on once a filter s time period has expired the AFS algorithm will check to see if the feedback filter is still necessary If no longer needed the notch filter will then slowly lift If the filter is still required to eliminate feedback the timer will be reset If the Live Filter Lift is off the notch filters will remain in place until they are cleared or until need e
8. or con sequential damages or from any delay in the performance of this warranty due to causes beyond their control Installation Recommendations FOR RACK MOUNT USE ONLY Install the AFS 224 in your rack with the provided rack screws When installed in a rack the unit should be positioned with enough room at least one 10 above the and 1U below the unit to allow proper ventilation The AFS 224 should not be mounted above or below anything that generates excessive heat Ambient temperatures should not exceed 113 F 45 C when equipment is in use Although the unit is shielded against radio frequency and electromagnetic interference extremely high fields of RF and EMI should be avoided where possible Basic Connection of the AFS 224 The AFS 224 has balanced inputs and outputs that can be used with any balanced or unbal anced line level device To connect the AFS 224 to your sound system refer to the following steps e Turn off all equipment before making connections e Mount AFS 224 in a standard width rack Install the AFS 224 in a rack with the rack screws provided It can be mounted above or below anything that does not generate excessive heat Ambient temperatures should not exceed 113 F 45 C when equipment is in use Although the unit s chassis is shielded against radio frequency and electromagnetic interference extremely high fields of RF and EMI should be avoided Make audio connections via XLR or 1 4 TRS jacks c
9. which are used to indicate the number of fixed and set filters within each channel This section of the manual is provided to give the user step by step instructions for setting up and optimizing the performance of the AFS 224 A Setting Gain Structure The four basic ways to hookup the AFS 224 to your system are as follows 1 Connected to the insert jack s on a microphone channel of a mixer 2 Connected to the insert jack s on the main outputs of a mixer 3 Connected to the subgroup insert jack s of a mixer 4 Connected inline w outputs of a mixer output of mixer to input of 224 output of 224 to amplifiers For maximum performance and proper operation the average input signal should consistently light the 0 dBu LED with the 10 dBu LED occasionally lighting Hookup methods 1 2 amp 3 above are the preferred way to connect the AFS 224 since the insert points on most mixers are pre output fader This allows the proper signal level to be fed to the AFS 224 without the chan nel or output fader affecting the level as the fader is moved up or down Be sure to check the mixer s manual for the nominal operating point for the insert jacks and then select the 4dBu or 10dBV switch on the back of the AFS 224 accordingly 3 AFS 224 User Manual dbx PROFESSIONAL PRODUCTS If no insert points are available then method 4 would be utilized In this situation be sure that the AFS 224 input level allows the 0 and 10 dBu LEDS to light a
10. AFS 224 User Manual dbx PROFESSIONAL PRODUCTS Application 4 Connected Inline with the Outputs of a Mixer This application is ideal for dedicated feedback suppression on the outputs of a mixing con sole This application provides the user with dual channels of 24 filters of feedback suppres sion per output channel of the mixing console I Connect the outputs from the mixer to the inputs of the AFS 224 2 Connect the outputs of the AFS 224 to the power amps 3 Apply power to the mixer and amplifiers For maximum performance and proper operation the input signal to the dbx 224 must cause the 0 dBu LED to light fairly consistently and the 10 dBu LED to light occasionally The input level to the amplifiers may have to be reduced in this situation so that they are not overdriven by the signal from the 224 Mixer Output to Input Channel AFS 224 Mixer Output to Input Channel 2 AFS 224 6 7 8 OutputA Output B dbx PROFESSIONAL PRODUCTS AFS 224 User Manual 10 Block diagram we Or 311 vy D sseddg O gt 5155152551525 222755155 e T 5 131 1914 mro LEEK 22018 SAV x PROFESSIONAL PRODUCTS AN ad sel 21801 329391 412 405592044 ow 34 1
11. Fax 801 568 7583 Table of Contents Defining the AFS 224 i Service Contact Info ii Warranty ii Installation Recommendations 1 Basic 1 Rear Panel Connections 2 Front Panel 2 User Setup ttn siete wines 3 Applications cea 7 Block Diagram ioniene iat naaa aa E ARST 10 ey 11 Table of Contents dbx PROFESSIONAL PRODUCTS AFS 224 Operation a R dbx PROFESSIONAL PRODUCTS Congratulations on your purchase of the dbx Professional Products AFS 224 AFS 224 Advanced Feedback Suppression processor was designed to provide state of the art feedback elimination processing while maintaining a simple and intuitive control interface From the powerful DSP module to the no nonsense user interface the AFS 224 provides all the process ing and control necessary for both installation and live use The AFS 224 is an absolute must for any live sound application Ten and twelve filter feedback elimination processors have become the de facto standard but
12. as the units Filter Lift capabilities The Live Mode of operation continuously updates filter placement which provides flexibility during a performance The Filter Lift feature automatically removes filter assignments that are no longer necessary which in turn maximizes sonic integrity The AFS 224 allows the user to optimize the elimination of feedback In the past graphic equal izers were used to eliminate feedback from a system This was an acceptable method for elim inating feedback but when this method was precision tested the result clearly showed that a single 1 3 octave EQ slider was removing approximately half of the signal power With the AFS the unit removes the feedback automatically and the proprietary precision AFS filters remove only a fraction of the frequency spectrum The diagram on the following page shows AFS as opposed to competitive feedback eliminators and conventional graphic EQs i AFS 224 User Manual dbx PROFESSIONAL PRODUCTS 5 6 AFS Feedback Elimination sf 3 Octave 20 600 700 800 11k 1 Hz For more information regarding dbx Advanced Feedback Suppression AFS technology please refer to the white paper section online at www dbxpro com Service Contact Info If you require technical support contact dbx Customer Service Be prepared
13. cordance with the following code GREEN and YELLOW Earth BLUE Neutral BROWN Live As colours of the cores in the mains lead of this appliance may not correspond with the coloured markings identifying the ter minals in your plug proceed as follows The core which is coloured green and yellow must be connected to the terminal in the plug marked with the letter E or with the earth symbol or coloured green or green and yellow core which is coloured blue must connect ed to the terminal marked N or coloured black core which is coloured brown must be nected to the terminal marked L or coloured red This equipment may require the use of a different line cord attachment plug or both depending on the available power source at installation If the attachment plug needs to be changed refer servicing to qualified service personnel who should refer to the table below The green yellow wire shall be connected directly to the units chassis Pu NEUTRAL BLUE ware EARTH GND GREENYEL GREEN WARNING If the ground is defeated certain fault conditions in the unit or in the system to which it is connected can result in full line voltage between chassis and earth ground Severe injury or death can then result if the chassis and earth ground are touched simultaneously WARNING FOR YOUR PROTECTION READ THESE INSTRUCTIONS KEEP THESE INSTRUCTIONS HEED ALL WARNINGS FOLLOW ALL INSTRUCTIONS
14. d for other frequencies D 2 Using Types in Live Mode As in Fixed Mode the AFS 224 offers several feedback suppression types These types con trol the width of the notch filter used to remove the feedback The Speech type uses wider notch filters allowing the AFS 224 to work faster The Music types provide sharper notch fil ters than the Speech type with up to 1 80th of an octave in the Music High type see AFS fil ter Q graph on the previous page Pressing the lt TYPE gt button switches between the dif ferent types You can select different types for both Live and Fixed Mode E Clearing Filters Fixed and Live To clear the Live filters press and hold the lt BYPASS gt button on the selected channel for approx imately two seconds The currently assigned live filter LEDs will flash If you wish to clear only the Live filters release lt BYPASS gt button at this time If you wish to reset all filters continue to hold the lt BYPASS gt button an additional two seconds until all filter LEDs are flashing At this point release the lt BYPASS gt button and all filters will be cleared F Other Functions The AFS 224 also offers the security feature of front panel lockout and the ability to link channels The following information provides instruction for both procedures F Front Panel Lockout To lockout all access to the front panel of the AFS 224 press and hold the channel 1 lt LIVE FILTER LIFT gt button until all of the fil
15. elect between either 4dBu or 10dBV nominal operating level Output Connectors Two types of output connectors are provided for output connec tions male XLR type connectors and 1 4 tip ring sleeve phone jack connectors Front Panel AFS 224 Front A CHANNELONE 12 0 Music LOW 6 Mi FIXED 0 MUSIC MED R 0 PROFESSIONAL PRODUCTS 8 i Input Level Bar Graph These four LEDs indicate input level of the AFS 224 Input level LEDs range from 10 to 18dBu IMPORTANT For maximum performance and proper operation the average input sig nal should consistently light the 0 dBu LED with the 10 dBu LED occasionally lighting Clip LED This LED indicates that there is signal clipping at the input Bypass This button bypasses the notch filters in the signal path by pressing once Pressing and holding the Bypass button is used to reset the filters For more information regarding filter reset please see the Clearing Filters in the User Setup Section Type This button is used to select the AFS type and to link Channel A and Channel B The AFS 224 offers several feedback suppression types which are Speech Music Low Music Medium and Music High Each selected Type controls the width of the n
16. erence that may cause undesired operation Operation of this unit within significant electromagnetic fields should be avoided e use only shielded interconnecting cables U K MAINS PLUG WARNING A molded mains plug that has been cut off from the cord is unsafe Discard the mains plug at a suitable disposal facility NEVER UNDER ANY CIRCUMSTANCES SHOULD YOU INSERT A DAMAGED OR CUT MAINS PLUG INTO A 13 AMP POWER SOCKET Do not use the mains plug without the fuse cover in place Replacement fuse covers can be obtained from your local retailer Replacement fuses are 13 amps and MUST be ASTA approved to BS1362 DECLARATION OF CONFORMITY Manufacturer s Name dbx Professional Products Manufacturer s Address 8760 S Sandy Parkway Sandy Utah 84070 USA declares that the product Product name dbx AFS 224 Note Product name may be suffixed by the letters EU Product option None conforms to the following Product Specifications Safety IEC 60065 1998 EMC EN 55013 1990 EN 55020 1991 Supplementary Information The product herewith complies with the requirements of the Low Voltage Directive 72 23 EEC and the EMC Directive 89 336 EEC as amended by Directive 93 68 EEC Vice President of Engineering 8760 S Sandy Parkway Sandy Utah 84070 USA Date June 9 2003 European Contact Your local dbx Sales and Service Office or Harman Music Group 8760 South Sandy Parkway Sandy Utah 84070 USA Ph 801 566 8800
17. he original purchaser and only in the United States 1 The warranty registration card that accompanies this product must be mailed within 30 days after purchase date to validate this warranty Proof of purchase is considered to be the bur den of the consumer 2 dbx warrants this product when bought and used solely within the U S to be free from defects in materials and workmanship under normal use and service 3 dbx liability under this warranty is limited to repairing or at our discretion replacing defec tive materials that show evidence of defect provided the product is returned to dbx WITH RETURN AUTHORIZATION from the factory where all parts and labor will be covered up to d bx PROFESSIONAL PRODUCTS AFS 224 User Manual i a period of two years Return Authorization number must be obtained from dbx by telephone The company shall not be liable for any consequential damage as a result of the product s use in any circuit or assembly 4 dbx reserves the right to make changes in design or make additions to or improvements upon this product without incurring any obligation to install the same additions or improvements on products previously manufactured 5 The foregoing is in lieu of all other warranties expressed or implied and dbx neither assumes nor authorizes any person to assume on its behalf any obligation or liability in connection with the sale of this product In no event shall dbx or its dealers be liable for special
18. on Fixed and Live Fixed mode is used to detect and remove feedback problems in the system due to microphone placement room modes etc Once set these filters are not removed until reset or cleared Live mode detects and removes feedback during a performance or event dbx PROFESSIONAL PRODUCTS AFS 224 User Manual 4 5 Ringing out a system Fixed mode filters are set before a performance in a process called ringing out a system This is done after all other system EQ ing has been done First bring down the main mix turn off all music sources and open all the mics Place the AFS 224 into fixed mode by pressing the lt MODE gt button for the channel lt MODE gt button lighting green indicates Fixed mode for that channel Select the channel s filter type by pressing the channel s lt TYPE gt button See Using Types in Fixed mode below Slowly turn up the main mix raising the gain of the system until feedback occurs The AFS 224 will detect and remove feedback by placing notch filters at the feedback frequency Continue to slowly raise the gain until all feedback has been eliminated or all fixed filters have been used this will be indicated by the flashing lt MODE gt button C 2 Using Types in Fixed mode The AFS 224 offers several feedback suppression types These are Speech Music Low Music Medium and Music High The selected type controls the width of the notch filter used to remove the feedback Music High uses very narro
19. onnectors according to application needs Both types of connectors for the inputs and outputs can be used for balanced or unbalanced connections The use of more than one connector at a time for the inputs could unbalance balanced lines cause phase cancellation short a conductor to ground or cause damage to other equipment connected to the AFS 224 More than one output may be used simultaneously as long as the combined parallel load is greater than 600Q Apply power to the AFS 224 Connect the AC power cord to the AC power receptacle on the back of the AFS 224 Route the AC power cord to a convenient power outlet away from audio lines The unit may be turned on and off from a master equipment power switch Since the AFS 224 consumes a relatively small amount of power the units may be left on continuously 1 AFS 224 User Manual dbx PROFESSIONAL PRODUCTS AFS 224 Rear CHANNEL 2 CHANNEL 1 1081 EN oll 1087 100 50 60 2 120772 Power Cord Receptacle Connects power to the AFS 224 Input Connectors Two types of input connectors are provided for input connections female locking XLR type connectors and 1 4 tip ring sleeve phone jack connectors The maximum input level that the processor can accept is 20dBu ref 0 775Vrms Operating Level Switch This button allows you to s
20. otch filter used to remove the feedback MUSIC HIGH uses very narrow notch filters minimiz ing the effect on the music whereas the SPEECH type uses much wider notch filters allow ing the AFS 224 to work faster The Type LED color and Frequency Q are listed below and a representative filter Q graph is shown on the next page Type LED Q Music High Red 1 80th Octave Music Med Yellow 1 20th Octave Music Low Green 1 10th Octave Speech Not Lit 1 51 Octave d bx PROFESSIONAL PRODUCTS AFS 224 User Manual 2 AFS 224 Filter Q s 3 3 2 2 E Music High 1 80th Octave 476 1 08 1 0 AE 1 2 Music Med 1 20 Octave 3 E 3 3 4E Music Low 1 10th Octave 4 u 5E gt 1 5th Octave gt 6E 6 7E 7 8E 8 ELLU OA AA 111 9 700 750 820 850 900 95k 1k 1 2 Hz Live Filter Lift Live Filter Lift provides maximum sonic integrity by removing unnecessary feedback filters This button is used to select the live filter lift times and are indicated as follows LED Lift Time Not Lit Lift Off Green 10 Seconds Yellow 10 Minutes Red 60 Minutes Mode This button is used to select FIXED button is green or LIVE button is red The Mode button is also used to set the number of filters For more information please see Section B Set Up AFS Filter LEDs The AFS 224 offers 24 filter LEDs per channel
21. put Input Channel Channel 2 AFS 224 Microphone In Microphone In OutputA Output B 7 AFS 224 User Manual dbx PROFESSIONAL PRODUCTS Application 2 Insert the Main Stereo Outputs of a Mixing Console This application is ideal for dedicated feedback suppression on the outputs of a mixing con sole This application provides the user with dual channels of 24 filters of feedback suppres sion per channel I Connect the stereo output inserts of the mixer to the inputs of the AFS 224 2 Connect the outputs of the AFS 224 to the insert returns of the console 3 Apply power to the mixer and amplifiers For maximum performance and proper operation the input signal to the dbx 224 must cause the 0 dBu LED to light fairly consistently and the 10 dBu LED to light occasionally Hookup at the insertion point since the insert points on most mixers are pre output fader This allows the proper signal level to be fed to the 224 without the channel or output fader affecting the level as the fader is moved up or down Be sure to check the mixer s manual for the nominal operating point for the insert jacks and then select the 4dBu or 10dBV switch on the back of the 224 accordingly ae dbx se 0 AFS 224 awam Coe eee ee en O Mixer Output to Input Mixer Output to Input Channel Channel 2 Insert AFS 224 AFS 224 Returns To Power Amp
22. rement or decrement the num ber Warning Changing the Total Number of Filters may remove feedback filters already set B 3 Selecting the Number of Fixed Filters Use the selected channel lt MODE gt button to toggle to the Set Number of Fixed Filters mode indicated by the selected channel s lt MODE gt button which will light green The current set ting for the Number of Fixed Filters is indicated by the number of Filter LED s lit for that chan nel To change the number of Fixed Filters use the selected channel s lt LIVE FILTER LIFT gt button to increment and the lt TYPE gt button to decrement the number of filters Each press of the button will increment or decrement the Total Number of Fixed Filters Press and hold each button to slowly increment or decrement the number Pressing the selected channel s lt MODE gt button will toggle between the Set Total Number of Filters and the Set Number of Fixed Filters mode for each channel If the channels of the AFS 224 are linked see F 2 Linking Channels the above procedure will set the same number of filters for both channels Warning Changing the Number of Fixed Filters may remove feedback filters already set B 4 Exit Setup Mode To exit the setup mode and return to operation mode press and hold the channel 1 lt MODE gt button until the Filter LED s light from left to right and repeat same as entering Setup mode C Using Fixed mode The AFS 224 offers two main modes of operati
23. s indicated above The input level to the amplifiers may have to be reduced in this situation so that they are not over driven by the signal from the AFS 224 Setup Mode The AFS 224 setup mode is used to set the Total Number of Filters and the Number of Fixed Filters in each channel The number of Live filters is the difference between the Total Number of Filters and the Number of Fixed filters Live filters Total Filters Fixed filters Note If channels are linked See F 2 Linking Channels the setup will assign the same number of filters to channel 1 and 2 Entering Setup Mode Press and hold the channel 1 lt MODE gt button until the Filter LED s light from left to right and repeat Release the channel 1 lt MODE gt button to enter the Setup Mode This is indi cated lt MODE gt button lighting yellow You are now in the Set Total Number of Filters mode B 2 Selecting the Total Number of Filters The Set Total Number of Filters mode is indicated by the channel lt MODE gt button lighting yellow when in the Setup mode The current setting for the Total Number of Filters is indi cated by the number of Filter LED s lit for that channel To change the Total Number of Filters use the channel lt LIVE FILTER LIFT gt button to increment and lt TYPE gt button to decre ment the number of filters Each press of the button will increment or decrement the Total Number of Filters Press and hold each button to slowly inc
24. ter LEDs light from outside to inside To unlock the front panel lockout press and hold the channel 1 lt LIVE FILTER LIFT gt button until the LEDs light from the inside to the outside F 2 Linking Channels To link both channels press and hold the Channel 1 lt TYPE gt button until all button LED s blink will set the unit into LINKED mode As feedback in either channel occurs notch filters will be placed in both channels to remove feedback To unlink channels press and hold the channel 1 lt TYPE gt button After the unit is unlinked both channels will behave indepen dently dbx PROFESSIONAL PRODUCTS AFS 224 User Manual 6 Applications Application Insert On the Microphone Channel This application is ideal for dedicated feedback suppression on microphone channels of a mix ing console This application provides the user with individual channels of 24 filter of feed back suppression per microphone Connect the channel insert output from the mixer to the input of the AFS 224 2 Connect the output of the AFS 224 to the insert return of the mixer For maximum performance and proper operation the input signal to the dbx 224 must cause the 0 dBu LED to light fairly consistently and the 10 dBu LED to light occasionally Be sure to check the 5 manual of the nominal operating point for the insert jacks and then select the 4dBu or 10dBV switch on the back of the 224 accordingly In
25. the engineering staff at dbx have never been content residing in the neighborhood of the sta tus quo So to raise the bar once again they went out and developed a dedicated feedback suppression processor that offers up to 24 filters per channel with widths as narrow as 1 80 of an octave To achieve these staggering numbers dbx utilized their patent pending AFS tech nology that had previously only been available in the upper echelon line of products and made it available in this stand alone processor In addition to the plethora of feedback suppression filters available the AFS 224 also offers selectable modes live filter lift and types of filtration which are all readily available via the intuitive user interface front panel This manual will be your guide to understanding the full functionality of the powerful AFS 224 series Defining the AFS 224 The dbx AFS 224 provide the user with the following features e dbx s patent pending Advanced Feedback Suppression AFS technology 24 Programmable Filters per Channel Stereo or Dual Independent Channel Processing Live and Fixed Filter Modes Selectable Filter Lift Times Application specific filter types include Speech Music Low Med and High Input Channel Metering 24 Segment Filter Metering per Channel XLR and TRS Electronically Balanced Input and Outputs The AFS 224 Advantage Key features that make the AFS 224 are its Fixed and Live modes of operation as well
26. to accurately describe the problem Know the serial number of your unit this is printed on a sticker attached to the rear or side of the unit If you have not already taken the time to fill out your warranty registration card and send it in please do so now Before you return a product to the factory for service we recommend you refer to the manu al Make sure you have correctly followed installation steps and operation procedures If you are still unable to solve a problem contact our Customer Service Department at 801 568 7660 for consultation If you need to return a product to the factory for service you MUST contact Customer Service to obtain a Return Authorization Number No returned products will be accepted at the factory without a Return Authorization Number Please refer to the Warranty information on the following page which extends to the first end user After expiration of the warranty a reasonable charge will be made for parts labor and packing if you choose to use the factory service facility In all cases you are responsible for transportation charges to the factory dbx will pay return shipping if the unit is still under war ranty Use the original packing material if it is available Mark the package with the name of the ship per and with these words in red DELICATE INSTRUMENT FRAGILE Insure the package prop erly Ship prepaid not collect Do not ship parcel post Warranty This warranty is valid only for t
27. w notch filters minimizing the effect on the music The Speech type uses much wider notch filters allowing the AFS 224 to work faster See Type in Front Panel section for descriptions and indicators AFS 224 Filter Q s 3 2 2 Music High 1 80th Octave 1 1 0 0 1E 1 2 Music Med 1 20th Octave 2 d E 3 3 4E Music Low 1 10th Octave 5E 5 1 5th Octave gt 6E 6 7E 7 8E 8 ELLA A A 2 700 750 820 850 900 95k 1k 1 2 During the filter setting process the filter type be changed by pressing the channels lt TYPE gt button This will change the filter type for the next filter and will not change exist ing filters When all fixed filters have been used new feedback occurrences will not be removed Pressing the lt MODE gt button will place the AFS 224 into Live mode indicated by the lt MODE gt button lit Red and feedback will continue to be removed If more fixed filters are needed reallocate more filters by following the steps in Setup Mode or clear the filters See section E Clearing Filters by pressing and holding the lt BYPASS gt button until all the Filter LED s blink and repeat the procedure above with a wider filter type D Using Live Mode Live Mode allows feedback filters to be set and removed based on changes in the environment and is designed to
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