Meyer M-1A - User Manual

Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, CA 94702
Operating Instructions
M-1A
Control
Electronics
Unit
The Meyer Sound M-1A is
an active signal processor
designed for use with Meyer
Sound UPA-1C and UM-1C
loudspeakers. lt is a single
channel device, and it
occupies a single 1
3
⁄
4
-inch
rack space. The functions
of the M-1A are:
■ Active crossover for bi-
amplication
■ Loudspeaker frequency
response and phase
response alignment
■ SpeakerSense™ driver
protection
+–
Input
Sub
In
Lo Hi
Sense
Lo
Out
Hi
Out
1/4 A
Hi Channel
+–
Lo Channel
Amplifier
Loudspeaker Cable
Input
1 Meter
Pigtail
Adapter
Red
Sense
Cable
Red
Black
Sense
Cable
Black
Connections
The M-1A operates at line level and is de-
signed to be the last component in the chain
before the power amplier. Connections to
the M-1A should be made according to the
diagram above.
1. Signal inputs to the M-1A may be either
balanced or unbalanced. For best sig-
nal-to-noise ratio, the average input level
should be at least 1 volt RMS. The M-1A
will accept peak inputs of up to +26 dBv
balanced, or +20 dBv unbalanced.
2. The Sub input is used only when the M-
1A is operated in conjunction with Meyer
Sound B-2, B-2A or B-2AEX subwoofer
Controllers.
3. SpeakerSense™ connections are made
from the output of the power amplier
back to the M-1A Sense inputs. The Hi
output of the power amplier must be
connected to the Hi Sense input, and the
Lo output of the power amplier to the Lo
Sense input in order for the SpeakerSense
driver protection circuitry to operate prop-
erly.
Note. Polarity of these connections does not
matter.
4. Signal outputs from the M-1A may be
either balanced or unbalanced. The max-
imum output levels before clipping are
+26 dBv balanced, +20 dBv unbalanced.
5. Connections between the power amplier
outputs and the Meyer Sound loudspeaker
used with the M-1A should be made ac-
cording to the instructions for the particular
loudspeaker (UPA-1C or UM-1C). These
connections must be veried for correct
polarity, and correct channel assignment
(Hi to Hi, Lo to Lo). Color codes given
in the diagram are those used for Meyer
Sound cables and adapters.
Note. The grounding strap on the M-1A rear
panel connects circuit ground (signal com-
mon) to earth ground (U-ground). Lifting this
strap from the terminal block disconnects
circuit ground from earth ground (the chas-
sis remains connected to U-ground). If hum
problems occur, this feature may be used to
control ground loops in the system.

Summary

M-1 A Connections

Signal Inputs

Details on balanced/unbalanced signal inputs, including optimal level and peak handling.

Sub Input Usage

Information on connecting the Sub input with specific Meyer Sound subwoofer controllers.

SpeakerSense Connections

How to connect amplifier outputs back to Sense inputs for driver protection.

Signal Outputs

Maximum signal output levels before clipping for balanced and unbalanced connections.

Amplifier to Loudspeaker Wiring

Guidelines for connecting amplifier outputs to loudspeakers, including polarity.

M-1 A Operation and Controls

System Operation Sequence

Steps for powering on the M-1A and power amplifier, and setting initial levels.

Preset Panel Controls

Explanation of Safe, VHF, and Lo Cut switches for system tailoring.

SpeakerSense Indicators

Description of Sense and Limit LEDs for monitoring signal presence and limiter activity.

Advanced Setup and Verification

Verifying Limiter Operation

Procedure to test limiter functionality using an oscillator or signal source.

Balancing Amplifier Gain

Method for matching voltage gain between Lo and Hi amplifier channels.

Sub Input Integration Details

Specific connection instructions for using the Sub input with B-2/B-2A/B-2AEX CEUs.

M-1 A Technical Specifications

Input;Output and Performance Specs

Details on input/output levels, impedance, hum, noise, and dynamic range.

Crossover, Delay, and Protection Specs

Specifications for crossover frequency, delay type, and driver protection circuitry.

Indicators, Controls, and Connectors

Listings of front panel indicators, controls, and connection types.

Power, Dimensions, and Weight

Information on power requirements, physical dimensions, and unit weight.

Meyer M-1A Specifications

General

Brand	Meyer
Model	M-1A
Category	Processor
Language	English