JBL Speaker MPC X100 100 Hz User Manual

MPC-X100 100 Hz Subwoofer Crossover  
For JBL MPC and MPA amplifiers  
Owners Manual and Installation Guide  
I. Description  
The MPC-X100 is a dual-channel 100 Hz crossover filter accessory for use with JBL MPC  
and MPA power amplifiers.  
The MPC-X100 is user configurable to fulfill these functions:  
• active crossover—Channel 1: 100 Hz low-pass; Channel 2: 100 Hz high-pass or full-range.  
• subsonic filter—programmable; preset @ 20 Hz to protect against damage from infrasonic signals.  
• ultrasonic filter—programmable; preset @ 20 kHz to protect against damage from ultrasonic signals.  
• CD horn EQ—for use in systems with uncompensated constant-directivity horns.  
Each channel has an electronically balanced input and bypassable low-pass and high-pass  
sections. Each filter circuit uses a 4-pole (24 dB/oct) Linkwitz-Riley alignment.  
An alternative to the MPC-X100, the MPC-XU is a universal crossover with selectable  
crossover frequency.  
The MPC-X100 installs onto the amplifier’s input card, where its settings are not easily  
accessible to the user. This makes the MPC-X100 ideal for installed or rental sound systems,  
since it practically eliminates the danger of unauthorized tampering with crossover setting or  
incorrect crossover output connections, as well as the loudspeaker damage that may result  
from such user tampering.  
Installing the MPC-X100 involves soldering a 10-pin and a 12-pin header into corresponding  
holes on the input card, a process that only qualified technical persons should attempt. We  
recommend that you enlist an authorized JBL service center to perform the task. See the  
installation section of this manual for more information.  
Figure 1 shows a block diagram of both channels of the MPC-X100:  
Programmable  
100 Hz  
Linkwitz-Riley  
Subwoofer  
Linkwitz-Riley  
Low-Pass Filter  
High-Pass Filter  
Output  
(factory preset @ 20 Hz)  
Channel 1  
jumper block: 3-pin  
header J101  
jumper block: 3-pin  
header J102  
(subwoofer)  
resistor network RN104  
Programmable  
Linkwitz-Riley  
Low-Pass Filter  
100 Hz  
Linkwitz-Riley  
High-Pass Filter  
High-pass or  
Full-range  
Output  
(factory preset @ 20 kHz)  
Channel 2  
jumper block: 3-pin  
header J201  
jumper block: 3-pin  
header J203  
jumper block: 3-pin  
header J202  
(high-pass or full-range)  
resistor network RN202  
& switch S201  
*TD-000084-00*  
Figure 1. Block diagram of the MPC-X100  
TD-000084-00  
Rev. A  
1
 
NOISE SHIELD  
#4-40 NUT  
NOISE SHIELD  
TAB  
CH. 1 GAIN CONTROL  
INPUT PANEL PCB  
Figure 3  
Figure 4  
8 If you need to make any adjustments to the MPC-X100 settings or if you need to record  
them, do so now, because the MPC-X100 will be inaccessible once the noise shield is  
installed and the input panel is re-installed into the amplifier chassis. See Section III,  
“Programming the MPC-X100,” below.  
9 Using a ¼-inch (6.3 mm) nutdriver, remove the outer 4-40 nut from the stud in the panel  
mounting bracket, next to Channel 1’s gain control potentiometer. Place the noise shield  
over the circuit board of the MPC-X100 (Figure 3) and bend the grounding tab down so  
its hole goes over the stud. Re-install the nut, and tighten it securely (Figure 4).  
10 Reconnect the ribbon cable to the input board connector. Press the locking clamp wings  
of the connector closed. You will feel them snap into place.  
11 Carefully reposition the input board/MPC-X100 assembly into the amplifier chassis and  
secure it by fastening the two mounting screws. Make sure the screws are tightened snugly,  
but do not over-torque them. Re-install the upper blank panel.  
Installation of the MPC-X100 is now complete, and the amplifier is now ready to be installed  
into the system.  
III. Programming the MPC-X100  
The MPC-X100 is preset for a 100 Hz crossover point; this  
frequency cannot be changed. The circuit board has four  
switches, six 3-pin headers, and two SIP resistor network  
sockets, all used for programming the module (see Figure 3).  
The numerical designations identify which channel the  
switch, header, or socket is part of: those designated by a 3-  
digit number starting in a 1 (for example, headers J101) are  
for Channel 1, while those starting in a 2 are for Channel 2.  
Figure 3. The MPC-X100’s switches, jumpers, and resistor networks.  
Setting input operating mode on amplifier or input card  
The input board or accessory on which the MPC-X100 is installed has provisions—switches or  
headers—for setting the operating mode of the amplifier. In the signal flow, the MPC-X100 is  
located after these switches or headers, so its operation is affected by the mode setting.  
Stereo or Parallel Mode Operation—With the amplifier in stereo or parallel mode, the  
MPC-X100 operates normally: Channel 1 provides a 100 Hz low-pass subwoofer signal to  
Channel 1 of the amplifier, while Channel 2 provides either a 100 Hz high-pass or a full-range  
signal. Most 2-way applications will require operating in parallel mode.  
3
 
Bridged Mode Operation—With the amplifier in bridged mono mode and driving a high-  
power subwoofer system, the MPC-X100 can be used as a subwoofer filter, taking full-range  
audio from Channel 1’s input and sending on a 100 Hz low-pass signal to the amplifier  
circuitry. For correct operation, bypass Channel 2 on the MPC-X100 board and use only  
Channel 1’s input and processing.  
Bypassing the filters  
To completely bypass the filter circuitry of a channel, set the jumpers on both Jx01 and Jx02  
across pins 1 and 2, which are the upper two pins on their headers (see Figure 4). Note: If  
you neglect to place jumpers on either header, no signal will pass on that channel. To  
bypass Channel 2 for bridged mode operation, set the jumpers on headers J201 and J202  
across pins 1 and 2.  
Figure 4  
Channel 1 (subwoofer): Programming the subsonic (high-pass) filter  
Bypass/enable headerTo use the subwoofer channels high-pass subsonic filter, set the  
jumper on header J102 across pins 2 and 3, which are the lower two pins. If you do not want  
any subsonic filtering, bypass the filter by setting the jumper across pins 1 and 2. Note:  
Subwoofers tend to sound best when used with suitable filtering, which prevents the  
amplifier and speaker from wasting power trying to reproduce frequencies that are too  
low. For best performance it is recommended that you bypass the high-pass filter only  
if there is suitable filtering elsewhere in the audio signal path.  
Switch S102 in  
"×1" position  
Resistor network  
in RN104  
20 Hz  
30 Hz  
40 Hz  
50 Hz  
120K  
82K  
56K  
47K  
Subsonic (high-pass) filter  
frequency table  
Setting frequencyTo set the corner frequency (at which the output is 6 dB down) of the  
high-pass filter, set switch S102 to ×1 (down) and choose the appropriate resistor network  
value for RN104. Use the high-pass table to select the right combination. See the appendix of  
this manual for keys to identifying the correct resistor network. Note: Switch S101 should  
also be set to ×1 (down).  
Inserting the resistor network—The factory preset frequency is 20 Hz. If there is a resistor  
network already installed in the socket, carefully pull it straight out. Insert the pins of the new  
resistor network into the socket holes and carefully press the network into the socket. Be  
careful to avoid bending the pins of the resistor network. Orientation of the resistor network  
is unimportant, as long as all 8 pins are well seated in the socket.  
Channel 2: Programming the ultrasonic (low-pass) filter and CD horn EQ  
Bypass/enable headerTo use the low-pass ultrasonic filter, set the  
Switch S201 in  
"×1" position  
Switch S201 in  
"×10" position  
Resistor network  
jumper on J201 across pins 2 and 3, which are the lower two pins. But if you  
do not wish to use the low-pass filter and want to bypass it instead, set the  
in RN202  
800 Hz  
120K  
jumper across pins 1 and 2. Note: Ultrasonic filtering is recommended to  
reduce susceptibility to RF and other types of interference.  
1000 Hz  
1200 Hz  
1600 Hz  
2000 Hz  
2500 Hz  
5000 Hz  
8000 Hz  
16000 Hz  
20000 Hz  
82K  
68K  
To engage the 100 Hz high-pass filter, place a jumper across pins 2 and 3 of  
header J202. To bypass the filter for full-range audio, place the jumper across  
pins 1 and 2. Note: if you need CD horn equalization, you must engage  
the 100 Hz high-pass filter also.  
56K  
47K  
250 Hz  
500 Hz  
800 Hz  
1600 Hz  
2000 Hz  
33K  
Setting frequencyTo set the corner frequency (at which the output is  
6 dB down) of the low-pass ultrasonic filter section, choose the appropriate  
resistor network value and switch setting for RN202 and S201, respectively.  
(Sx01 is a ×10 range switch. In its upper position, the frequency range is ×10;  
18K  
12K  
5.6K  
4.7K  
in the lower it is ×1.) Use the low-pass table at left to select the right combi-  
nation. See the appendix of this manual for keys to identifying the correct  
resistor network. Note: Switch S202 should always be set to ×1 (down).  
Ultrasonic (low-pass) filter  
frequency table  
The high-pass frequency is fixed at 100 Hz and cannot be changed.  
4
 
Inserting the resistor network—The factory preset frequency is 20 kHz. If there is a  
resistor network already installed in the socket, carefully pull it straight out. Insert the pins of  
the new resistor network into the socket holes and carefully press the network into the socket.  
Be careful to avoid bending the pins of the resistor network. Orientation of the resistor  
network is unimportant, as long as all 8 pins are well seated in the socket.  
CD Horn Equalization (Boost)—In addition to enabling the 100 Hz high-pass filter at  
J202, if you opt for CD horn equalization you must place a jumper at J203 as well. The MPC-  
X100 offers two equalization curves for CD horn correction:  
• For +6 dB of boost at 20 kHz, place the jumper across pins 1 and 2 of J203.  
• For +10 dB of boost at 20 kHz, place the jumper across pins 2 and 3 of J203.  
• To bypass the CD horn equalization, do not place a jumper across any pins on J203.  
Pins 1 & 2 Pins 2 & 3  
None  
The table at left is a summary of the jumper  
settings for the MPC-X100.  
Function  
Header  
J101  
J102  
J102  
J103  
J201  
J201  
J202  
J202  
J203  
J203  
J203  
J201, J202  
J203  
All operation  
X
Bypass subsonic  
X
Channel 1:  
(subwoofer)  
Enable subsonic  
X
All operation  
X
Bypass ultrasonic  
X
X
X
X
Enable ultrasonic  
Bypass 100 Hz high-pass  
Enable 100 Hz high-pass  
Disable CD horn boost  
CD horn boost, +6 dB @ 20 kHz  
CD horn boost, +10 dB @ 20 kHz  
Bridged mono  
Channel 2:  
X
X
X
X
X
IV. Typical configurations  
Subsonic Filter (Infrasonic Filter)  
Applications: Subsonic filters are commonly used in sound installations to filter out rumbles  
and other inaudible or unwanted low frequency signals and to protect speaker tuned vented  
speakers from damage due to excessive energy below the tuning frequency.  
For a subsonic filter, determine the lowest useable frequency that the speaker can safely  
handle and set the high-pass filter to that frequency. Typical subsonic filters are set at 50 Hz,  
40 Hz, 30 Hz or 20 Hz.  
Program settings:  
1 Set J102 to enable the high-pass filter by placing jumper across pins 2 and 3.  
2 No jumper on J103.  
3 Insert proper resistor network in RN104 socket.  
5
 
Ultrasonic Filter  
Applications: An ultrasonic filter is useful for minimizing RF interference, oscillations,  
leakage or aliasing from digital devices, or other signals that are too high in pitch to hear but  
may wreak havoc in an amplifier system.  
Typical ultrasonic filters are set at 16 kHz or 20 kHz.  
Program settings:  
1 Set J201 to enable the low-pass filter by placing jumper across pins 2 and 3.  
2 No jumper on J203 unless you need CD horn equalization.  
3 Insert proper resistor network in RN202 socket.  
CD Horn Equalization Filter  
Applications: A constant directivity horn requires a 6 dB per octave boost at high frequen-  
cies to provide a flat frequency response. On the MPC-X100 you must use the CD horn  
equalization in conjunction with the 100 Hz high-pass filter.  
Program settings:  
1 Set J202 to enable the 100 Hz high-pass filter by placing jumper across pins 2 and 3.  
2 Set J203 to select the EQ curve you desire: across pins 1 and 2 to +6 dB at 20 kHz, or  
across pins 2 and 3 for +10 dB at 20 kHz.  
Full-range  
speaker system  
F =  
C
100 Hz  
MPC-X100  
Subwoofer  
2-Way Active Crossover  
This configuration routes the frequencies below 100 Hz to amplifier Channel 1, which will  
driver the subwoofer(s), and the frequencies above to Channel 2, which will drive the full-  
range (typically, woofer + high frequency as passive 2-way, or woofer + midrange + high  
frequency as passive 3-way) speaker(s). Using the MPC-X100 as a crossover requires that you  
drive both amplifier inputs with the same full-band signal.  
Program settings:  
1 On the input module, set the amplifer mode to parallel. Alternately, you could use a Y-  
cable to provide the same signal to both channel inputs.  
Channel 1:  
2 Subsonic (infrasonic) filter—If you need subsonic (infrasonic) filtering, set J102 to enable the  
high-pass filter by placing jumper across pins 2 and 3, and insert a resistor network into RN104  
corresponding to the roll-off frequency you desire. If you do not want subsonic (infra-  
sonic) filtering, set J102 to disable the high-pass filter by placing jumper across pins 1 and 2.  
6
 
Channel 2:  
3 Set J202 to enable the Channel 2’s 100 Hz high-pass filter by placing jumper across pins 2  
and 3.  
4 CD horn EQ—If you need equalization for a constant-directivity horn, set a jumper on  
J203 for the amount of boost you need. If you do not want CD horn equalization, do not  
place any jumper on J203.  
5 Ultrasonic filtering—If you need ultrasonic filtering, set a jumper on J201 across pins 2 and 3  
to enable Channel 2s Low-pass filter and insert a resistor network into RN202 that  
corresponds to the desired roll-off frequency. If you do not want any ultrasonic filtering,  
set the jumper on J201 across pins 1 and 2 to bypass the low-pass filter.  
V. Warranty & Contacting JBL  
These products are designed and backed by JBL Professional, the world leader in sound  
reinforcement. For complete JBL warranty information, to order replacement parts or to ask  
for clarifications to this manual, contact JBL Professional:  
Within the United States: Contact the Applications Dept, JBL Professional, PO Box 2200, 8500  
Balboa Blvd, Northridge CA 91329 USA. In the USA you may call Monday through Friday  
8:00 a.m. to 5:00 p.m. Pacific Coast Time: (818) 894-8850.  
In other areas throughout the world: Contact the JBL Professional Distributor in you country.  
A list of JBL Professional Distributors and U.S. Service Centers can be attained from the JBL  
Professional website: www.jblpro.com.  
7
 
Appendix  
Identifying resistor networks  
Use this chart to identify the values of the resistor networks. See the tables on page 4 to find  
the correct values for the desired filter frequencies.  
RESISTANCE CODE  
2.7K 272  
3.9K 392  
4.7K 472  
5.6K 562  
6.8K 682  
8.2K 822  
10K 103  
12K 123  
15K 153  
18K 183  
20K 203  
22K 223  
27K 273  
33K 333  
39K 393  
47K 473  
56K 563  
68K 683  
Use only these three digits to  
determine resistance code.  
Disregard the other  
numerals and letters.  
JBL Professional 8500 Balboa Boulevard, P.O. Box 2200 Northridge, California 91329 U.S.A.  
A Harman International Company  
MPC-X100 MANUAL 3/99  
 

Insignia Flat Panel Television NS LCD19W 09 User Manual
Invacare Mobility Aid Atlas User Manual
IOGear Network Card GUWA200 User Manual
Jasco Indoor Furnishings ZWAVEKIT User Manual
JVC Car Video System KV MH6510 User Manual
JVC TV VCR Combo TV 20F243 User Manual
Kenmore Cooktop 3241 User Manual
Kenwood Car Stereo System KDC 152 User Manual
Kettler Patio Furniture 01072 000 User Manual
Kramer Electronics Speaker SPK C411 User Manual