MODEL MPX500
MICROPHONE MULTIPLEXER
Introduction
Intended for use with the Dolby CP500 Digital Cinema Processor, the Dolby
Model MPX500 Microphone Multiplexer ensures rapid and accurate theater
speaker equalization by enabling the simultaneous use of as many as four
microphones (supplied) placed throughout the auditorium.
The MPX500 rapidly switches between the four microphones and sends their
outputs to the CP500 over the special 31-meter (100-ft.) Dolby Cat. No. 582
input/output cable (supplied). Digital circuitry within the CP500 then averages the
mic outputs for display on its built-in real time analyzer and subsequent EQ
adjustments. This eliminates the time-consuming process of moving a single
microphone to different locations and manually averaging the results.
Four high-quality electret microphones are supplied with the MPX500 along with
6-meter (20-ft.) connecting cables that adapt the microphones' standard XLR
connectors to the “mini-XLR” style input connectors on the MPX500. The Cat.
No. 582 input/output cable for connecting the MPX500 to the CP500 contains two
individually shielded pairs, one for distribution of bi-directional RS-232 control
signals and the other for the multiplexed microphone signal.
A built-in microcontroller chip is programmed to control microphone selection,
switching rate between microphones, and the MPX500's LED display. There are no
user adjustments on the MPX500 itself.
Unit Set-Up
Position the MPX500 Multiplexer centrally in the listening area and connect the
four microphones to it using the four Cat. No. 581 adapter cables. Position the
microphones in the room so that they are substantially in the reverberant field
rather than receiving mostly direct energy from the speakers. A typical microphone
