1
MPC-XU Universal Crossover
For JBL MPC and MPA amplifiers
Owner’s Manual and Installation Guide
I. Description
The MPC-XU is a dual-channel universal crossover filter accessory for use with JBL MPC
and MPA power amplifiers.
The MPC-XU is user configurable to fulfill these functions:
active crossover
bandpass filter
subsonic filter
ultrasonic filter
The MPC-XU allows independent filtering of the two audio channels. The choices are:
high-pass filtering (selection of 19 frequencies)
low-pass filtering (selection of 17 frequencies)
bandpass filtering (selection of any combination of the high-pass or low-pass frequencies)
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-XU, the MPC-X100 is preset at 100 Hz for use only as a
subwoofer crossover.
The MPC-XU installs onto the amplifiers input card, where its settings are not easily acces-
sible to the user. This makes the MPC-XU 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-XU 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 one channel of the MPC-XU:
Programmable
Linkwitz-Riley
Low-Pass Filter
Programmable
Linkwitz-Riley
High-Pass Filter
Figure 1. One channel of the MPC-XU
*TD-000082-00*
TD-000082-00
Rev. B
