JBL M9500 User's Manual
Contents
1. position The room itself should be quiet well damped and free of obvious flutter echoes or standing waves Connect the loudspeakers to the networks using the cables provided Note that there are different cables for high frequency and low frequency hookup they cannot be intermixed For positive contact insert the Speakon connectors and tum them one eighth tum clockwise Electronic Options Your next concem is the amplifier loudspeaker operating mode The various hookup options are shown in Figure 1 We will describe each of these options Option A single full range amplifier This mode of operation requires a relatively large high quality amplifier capable of delivering up to 800 watts per channel into 4 ohms Note that all sections of the network are connected in parallel with the straps provided Option B bi wiring In this mode identical power amplifier sections are fed full range program one amplifier is connected to the high frequency portion of the system and the other is fed to the low frequency sections in parallel Many users will use a large stereo amplifier to drive the low frequency sections and a smaller one for the high frequency sections Make sure that the stereo amplifier used for the paralleled low frequency sections can deliver the necessary power into 4 ohms Option C tri wiring This mode of operation is similar to B but with each low frequency section driven by its own amplifier In this case eac2. M O NI TOR LOUDSPERAKERS OWN ERS MANUAL M9500 GENERAL SYSTEM DESCRIPTION The JBL M9500 monitor loudspeaker system represents a refinement of the principles that have guided J BL s high level monitor system design over the last thirty years In keeping with contemporary monitoring practice the system is essentially of two way design A hom compression driver section covers the frequency range from 650Hz to20kHz Located above and below the high frequency section are mirror imaged low frequency transducers in ported enclosures The stereo pair of loudspeakers exhibits both vertical and horizontal symmetry for effective point source radiation and for accurate stereophonic imaging All transducers make use of shielded neodymium magnets and the systems can be used in proximity to video monitors with no interference The M9500 system uses stand alone dividing networks that facilitate various electronic options including bi wiring tri wiring and biamplification The networks are designed around the finest components available and make use of dc bias on the capacitors for greater linearity A single M9500 system is capable of producing sine wave out put levels of 110 dB Lp at one meter with extremely low distortion In terms of wide band program this translates into levels of 120 dB Lp for the stereo pair at normal listening distances of 2 and 3 meters The enclosures are made of thick sections of medium density fiber
3. board liberally braced and have an attractive scuff resistant finish Unpacking and Inspection The complete M9500 system is shipped in eight containers as detailed below 2 Lower low frequency enclosures 2 High frequency hom enclosures 2 Upper low frequency enclosures 1 Dividing networks 2 networks in one package including 6 hook up cables and 4 9 volt batteries 1 Low frequency grilles 4 in one package Make sure that you have all containers Unpack them carefully and inform your J BL dealer of any sign of damage It is recommended that you save the packaging for future use System Setup The M9500 systems are modular each consisting of a stack of three separate enclosures The larger of the bass enclosures are placed at the bottom and the high frequency hom modules stack on top and are aligned by the screws that protrude on the bass section The smaller bass modules are placed on top of the high frequency modules and are similarly aligned We recommend that you do not assemble the M 9500 systems until you have determined their best location in your listening room or control room In general the listening angle for best stereo imaging should be in the range from 45 to 60 degrees and the loudspeakers should be placed no closer than about 25 or 30 cm 10 or 12 from the wall behind them Sidewalls should be somewhat farther away and the loudspeakers should be toed inward toward the primary listening
4. e do LA e factor Q of the H9500 O o 50 100 200 500 1000 2000 5000 10000 20000 Frequency Hz Overall system on axis pressure response and impedance are shown in Figure 6 The contributions of the paralleled low frequency sections and the high frequency section are shown individually along with their acoustical summation The overall slopes in the crossover region are a combination of electrical network and acoustical response M9500 Figure 6 On axis response hee or of M9500 Individual contributions of paralleled TN low frequency transducers ica and high frequency section MM are shown along with their s summation The impedance curve is also given showing a minimum value of 3 ohms in the 100 Hz range 100dB o S e aas 2 3 4 567890 152 3 4 5678910 15 2 3 4 5678910 15 2 100 1000 10000 The second and third harmonic distortion of the system is shown in Figure 7 Here the system is driven with sine wave input to produce an output of 96 dB Lp at a distance of 1 meter An output of 96 dB with a sine wave input corresponds to extremely high system output with wide band program material Distortion curves have been raised 20 dB and the val ues se
5. en here lie well below 1 for the lowest frequencies up to 4 5 khz reaching a value of only 1 6 at 10 kHz Not many loudspeakers can demonstrate such low levels of distortion as shown here N p A Figure 7 Second and third WH HATNA UU harmonic distortion for A se Regra sis fundamental of 96 dB Lp at Hint aov 1m HHHH Dash Third Harm tt U U y a distance of 1 meter Distortion raised 20 dB FIT 2 3 4 5 678910 15 2 3 4 5678910 15 2 3 4 5 678910 15 2 100 1000 10000 Care and Maintenance of the System Your M9500 monitors should give years of trouble free service Normally the only routine maintenance will be cleaning The grilles may be cleaned of dust gently with a vacuum cleaner using a brush attachment If there should be stains on the grille a soft bristle brush moistened with a dilute mixture of water and dishwashing detergent may be used The same mixture may be used for cleaning the enclosure finish itself if it has become smudged As mentioned before the 9 volt batteries in the dividing net works will last perhaps as long as their normal shelf life You may expect them to last at least 5 years If the LED no longer lights remo
6. frequency response of the M9500 system was care fully established by making a series of measurements over frontal angles of 60 in both vertical and horizontal planes This allows for optimal listening over a wide area The frequency response averaged over the 60 horizontal and vertical angles measured from 200 Hz to 20 kHz is shown in Figure 4 Here the network High Frequency trim is set in its zero position The slight downward trend was incorporated based on extensive listening tests to contemporary pop rock and classical recordings 10 Figure 4 Averaged frontal angle response 60 HH horizontal and vertical of hs M9500 from 200 Hz to 20 kHz de EH 8 Relative level dB 30 2 3 4 567890 15 2 3 4 567890 15 2 3 4 5 678910 15 2 100 1000 10000 The directivity index DI of the H9500 hom is shown in Figure 5 The smoothly rising DI is a consequence of the gradual narrowing of the vertical dispersion angle above 2 kHz and contributes to the overall flatness of the high frequency response of the system Tiel pra AT on ie op ae ES 100 Figure 5 Plot directivity index DI and directivity Sur
7. h low frequency amplifier section will look into 8 ohms Figure 1 Electronic hookup options views of the rear panel of the dividing network A single fullrange amplification B bi wiring with two amplifiers C tri wiring with three amplifiers and D biamplification with extemal electronic dividing network and separate high and low frequency amplifiers A Biamp HF Norm Ei q To M9500 Input iz A B q To M9500 Sl q To M9500 M MM E Input Option D biamplification This mode of operation requires a dedicated electronic dividing network crossing over at 650 Hz We recommend the J BL DX 1 with internal compensation made for the M 9500 system If this mode is used make sure that the screwdriver adjustment on the back of each network is set in the biamp position HF out Biamp HF Os Norm x Electronic dividing High frequency trim switches on the Inu network Lo BE O Os 650 Hz crossover oy back of the networks provide three set ai tings zero plus and minus so that the systems can be trimmed for the acoustical characteristics of the listening space Regardless of the operating mode you choose we recommend that only the finest hookup wire be used between the ampli fiers and dividing networks We recommend that the wire size be no smaller than 3 3 square millimeter cross section 12 AWG The inputs to the networks ca
8. inted in USA on recycled paper 9 95 H A Harman International Company Part No J BLM9500M
9. n accommodate spade lugs pins bare wire or individual banana connectors The intemal 9 volt battery that is used to bias the capacitors will normally last at least 5 years You may test it by pressing the gold logo on the front of the network If the LED on the front of the network illuminates the battery is functional and need not be replaced Di tal h Front The iecast aluminum ousing __ ront cover Transducers DS H Silver plated pole piece Ww TEA Serpentine phone plug KZ ZA ZA Aquaplas dusted titanium diaphragm WEZ ZA Foam acoustic pad Top plate Neodymium magnet Return circuit Threaded mounting holes Throat Screen Aluminum shorted turn Copper shorted turn Cooling vent 1of 3 Neodymium magnet Return circuit Edgewood aluminum ribbon voice coil Centering spider Diecast frame magnet chassis Fiberglas Aquaplas composite cone Foam compliance Figure 2 Cutaway view of J BL 475Nd high frequency compression driver Note the curved equalized paths from the diaphragm to the driver s output Figure 3 Cutaway view of J BL 1400Nd low frequency transducer Note both aluminum and copper shorting rings To M9500 The J BL model 475Nd compression driver used in the M9500 has a smooth titanium dome 101 millimeters in diameter that has been lightly coated with Aquaplas damping compound Its aluminum ribbon voice coil o
10. perates in a magnetic flux field of 1 65 tesla 16 500 gauss Mid band efficiency is 20 while at the peak value of driver impedance it is in excess of 50 The driver uses J BL s Coherent Wave phasing plug which provides equalized path lengths from all sections of the diaphragm to the driver s output The driver is mounted on the H9500 hom a design used only in this system that provides smooth loading down to 500 Hz and exhibits consistent horizontal dispersion over its operating range There are two J BL model 1400Nd low frequency transducers in each loudspeaker system A single 1400Nd is capable of handling instantaneous input signals of 600 watts corresponding to a midband peak output of 118 dB Lp ata distance of one meter The transducer s second and third harmonic distortion have been reduced through the use of J BL s traditional aluminum shorting ring at the base of the pole piece as well as through the use of a copper shorting ring on the top plate adjacent to the voice coil The transducers make use of J BL s Vented Gap Cooling in which forced air generated by cone motion removes heat produced by the voice coil Each driver is mounted in its own ported enclosure and the two enclosures are stagger tuned to provide smoother and more extended low frequency response Cutaway views of the high frequency and low frequency transducers are shown in Figures 2 and 3 Typical System Performance Measurements The high
11. ve the acrylic door on the front of the network and replace them System Specifications Acoustic and Electrical Specifications Sensitivity 95 dB for 2 83 V 1 meter Rated Impedance LF parallel 4 Ohms Minimum Impedance 3 0 Ohms 100 Hz Frequency Response 35 Hz to 20 kHz half space Crossover Frequency 650 Hz System Polarity EIA positive voltage to red terminal produced outward cone motion System Components and Physical Specifications Low Frequency Transducer 1400 Nd High Frequency Transducer 475 Nd Hom Assembly H9500 Dividing Network N9500 Enclosure Volumes 78 liters 2 8 cu ft 35 Hz tuning upper LF 115 liters 4 1 cu ft 28 Hz tuning lower LF System Dimensions 140 mm H x 330 mm W x 403 mm D 55 H x 15 13 W x 15 88 D Total depth including hom 521 mm 20 5 Weight 38 2 kg 84 Ibs upper LF 54 5 kg 120 Ibs lower LF 37 3 kg 82 lbs hom assembly J BL continually strives to improve its products New materials produc tion methods and design refinements are introduced into existing models without notice as a routine expression of our design philosophy For this reason J BL M9500 Series Loudspeakers may differ in some respect from their published specifications and descriptions but will always equal or exceed the original specifications unless otherwise stated J BL Consumer Products Inc 80 Crossways Park West Woodbury NY 11797 8500 Balboa Blvd Northridge CA 91329 800 645 7484 Pr
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