AKG CM12/8 Manual page 18

3. Installation
Installing the CM12/8 properly is simple, and only requires attention to a few issues. The CM12/8
should be used in a grounded metal rack. More than one CM12/8 may be used if more than 12
inputs are necessary. The 9-pin Audio Link In/Out D-sub connectors allow the audio paths of mul­
tiple CM12/8s to be interconnected. The CM12/8 manual shows the correct interconnection for
multiple CM12/8s.
When using multiple CCM12/8s in an installation, a unique LecNet address must be assigned to
each CM12/8 if computer control is desired. The factory default LecNet address is 134. The LecNet
address may be set from the "LecNet Address:" menu item.
Line input connections should be made with good quality braid or foil shielded twisted pair. The
shield should be used for the ground (Pin 1) connection. If an unbalanced signal is used, the
unbalanced signal lead should be connected to the "+" input terminal, while the unbalanced
ground lead should be connected to both the "-" and ground terminals of the input connector.
PWR
EXPANSION
IN
OUT IN
(CH40)
20 VAC
PWR
EXPANSION
IN
OUT IN
(CH40)
20 VAC
PWR
EXPANSION
IN
IN
(CH40) OUT
20 VAC
Output connections can be made balanced or unbalanced. If an unbalanced connection is
desired, simply connect the unbalanced signal lead to the "+" output terminal, and the unbal­
anced ground lead to the output ground terminal. Leave the "-" output terminal unconnected.
The rear panel Output Level dip switches allow the nominal output level to be changed from line to
mic. The Output Level switch introduces approximately 40dB attenuation to the output signal. This
allows proper output level matching to mic level inputs, such as some types of tape recorders.
MEMORY
PRESETS
LecNet
1 2 3 4
(RS232)
1 2 3 4 5 6 + – + – + – + –
MEMORY
PRESETS
LecNet
1 2 3 4
(RS232)
1 2 3 4 5 6 + – + – + – + –
MEMORY
PRESETS
LecNet
1 2 3 4
(RS232)
1 2 3 4 5 6 + – + – + – + –
Figure 2 - Connecting multiple CM12/8 units together
INPUTS
5 6 7 8 9 10 11 12
+ – + – + – + – + – + – + – + –
INPUTS
5 6 7 8 9 10 11 12
+ – + – + – + – + – + – + – + –
INPUTS
5 6 7 8 9 10 11 12
+ – + – + – + – + – + – + – + –
18
CM12/8
CM 12/ 8
MATRIX MIXER
AUDIO LINK
IN OUT
CM 12/ 8
MATRIX MIXER
AUDIO LINK
IN OUT
CM 12/ 8
MATRIX MIXER
AUDIO LINK
IN OUT