ATC Group SCM200 User Manual page 5

SCM200/300ASL/P4
I n s t a l l a t i o n c o n t ' d
5 . S y s t e m C o n n e c t i o n s
Three cable connections are required for each P4
and monitor: one for mains power, one for the
audio signal and one for the speaker cable.
The mains cable is specifically supplied to comply
with local statutory safety approvals and
alternatives should not be substituted. If you intend
to use your monitors in an alternative territory
please contact ATC for advice. The mains
connection must always be earthed.
The signal cable and plug (not necessarily supplied)
should be of a good quality and XLR terminated.
Poor cable and plug quality will compromise the
performance of your monitors.The signal input pin
configuration is illustrated in Diagram 1.
Custom made 5 metre speaker cables and plugs
are supplied as standard with the P4. Speaker
cables of up to 10 metres are available. Runs up to
20 metres may be made up by splicing heavier
2)
gauge (4mm cable to 10 metre lengths.The splice
point should be 0.5 metres before the connector.
The 8-pin speaker connector scheme is illustrated
in Diagram 2.
6 . S i g n a l C a b l e O p t i o n s
Balanced cable configuration is the preferred
option, however unbalanced connection is
possible. Diagrams 3 and 4 illustrate the signal
cable connections required for each option.
Balanced (XLR to XLR) connection offers lower
noise and better immunity to "hum" pick-up.
Unbalanced (XLR to Phono or Two Pole Jack)
connection carries risk of hum caused by multiple
signal earths.
Hum problems resulting
connection may be reduced by making ONE of the
following modifications to the signal cable
connections: If the driving preamplifier (or desk) is
"double insulated" (i.e. has no mains earth),
disconnect the signal cable screen at the RCA
Phono plug end. Alternatively, disconnect the signal
cable screen at the XLR end.This second option will
make the source the reference signal earth.
4
from unbalanced
Diagram 1 - input connection pins
Pin 2, Signal (hot)
Diagram 2 - speaker plug
Pin Connection
A LF 1 Positive
B LF 2 Positive
G
C MF Positive
D HF Positive
F
E HF Negative
F MF Negative
G LF 1 Negative
H LF 2 Negative
Diagram 3 - balanced cable
3 Pin Male XLR
Two Core Screened Cable
Connector
2
3
1
To Monitor Input
Diagram 4 - unbalanced cable
3 Pin Male XLR
Two Core Screened Cable
Connector
2
3
1
To Monitor Input
Pin 1, Screen
Pin 3, Signal (return)
A
B
H
C
E D
3 Pin Female XLR
Connector
Hot
Return
Screen
To Source Output
Phono (RCA)
Connector
Hot
Return
Screen
To Source Output
2
3
1