Emtech Electronics RCM-82B User Manual

RCM Installation and Application Notes

RCM-42B and RCM-82B

06-12-2003

Emtech Electronics, Inc. 564 So. 1325 West, Orem, Utah 84058 1-800-371-2102 1-801-426-8333

RCM-42 and RCM-82 Installation and Application Notes

Quick Start Installation Guide for the RCM-42B & RCM-82B

Description:

The Emtech Electronics Room Combining Matrices are designed to simplify the process of connecting sound systems
in multiple rooms. The RCM-42B allows the sound systems from up to four rooms to combine in any combination
desired, while the RCM-82B does the same for up to 8 rooms. Each room may be operated independently, or it may be
assigned to either of two program groups, where it shares program material with any other room assigned to that same
group. The input channels of the matrix are normally directed back to their corresponding output.

Each room control has a Group A control input signal and a Group B control input signal (see figure 1). When either of
these control inputs are connected to ground, (with a switch closure to ground) the corresponding local input is
redirected to one of two internal busses, Group A or Group B which in turn are directed to the RCM output for that
room. If the control inputs are left in an open (switch is open) condition, the local material for that room is connected
to that room's output of the RCM only.

In any event, if program Group A or B are selected, all of the mic or line inputs that are available for that room in the
local position, continue to be available in the Group A or B positions.

Selecting between either of the two program groups is accomplished with an SPDT switch with a center off (open)
position. The use of solid state analog switches eliminates pops or clicks when switching. Signal level remains constant
as rooms are switched in or out of a group. The balanced inputs and DC logic buss combining controls allow long input
and control lines to the unit. If you are using the Emtech Electronics IA-204R amplifiers in your application, the
previously mentioned SPDT switch is built into the front panel of each amplifier. If you are using other amplifiers and
mixers, you can order from two decora style switch panels, RCM-KS (key-switch version) and RCM-S (standard
rocker style switch) from Emtech that provides the needed switch for each room.

Installation:

The RCM-42B and RCM-82B are fully remote controlled and can be placed in any convenient location. The unit may
be mounted to a wall or other flat surface using four #6 screws through the holes in the mounting flanges. All
connections to the unit are made by means of removable terminal connectors. the RCM can be mounted and then easily
wired at a later time. Avoid installing the unit in close proximity to large power transformers or power lines. (AC
current hum and noise may be introduced into the audio program.)

The RCM-B units now come with their own 24 volt DC power supply. You make the power connection via the DC
power jack on each unit. All other connections are made via 8-pin terminal connectors. Figure 1 includes a picture of
the 8-pin terminal connector.

2003, Emtech Electronics, Inc. All rights reserved.

2

RCM-42 and RCM-82 Installation and Application Notes

The input connection terminals are shown in Figure 1. The input signals can come from any balanced or unbalanced
line level source such as a mixer/amplifier. The shield of a balanced line should be connected to the terminal marked
GND on the matrix. When the source is unbalanced, strap the "input -" terminal to the GND terminal. Whether the
source is balanced or unbalanced, shielded audio cable should be used for these connections to minimize noise and hum
pickup. The output connection terminals are also shown in figure 1. The output signal can be sent to any line level
input, such as a mixer/amplifier. As with the output connections, shielded audio cable should be used.
The two control inputs terminals for each room/buss are marked GROUP A and GROUP B as shown in Figure 1.
These two connections can be wired to remote switches; a simple closure to ground will then assign that room to the
corresponding combining group. When Group A and Group B control terminals are open, (not connected to ground)
the input signal is simply routed back to its corresponding room output.

Figure 1: Terminal Connections on RCM-42B

2003, Emtech Electronics, Inc. All rights reserved.

3