User manual

1.3 Signal Cable Options
Balanced cable configuration is the preferred
option,however unbalanced connection is possible.
Diagrams 2 and 3 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 from unbalanced
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.
Installation
4
C4/C5/C6/C7 Active
1.4 Operation
The C4,C5,C6 and C7 are connected to the mains and signal cables via sockets on
the rear panel.The rear panel also carries the mains switch and fuse holder. Each
feature is described below.
• Mains Inlet:The supplied mains power lead (appropriate to the local territory)
should be connected here.Ensure that the mains voltage specified on the panel
(above the input socket) corresponds with the local supply.
• Power Switch:Switches on the speaker.When switched on the indicator on the
back of the monitor will illuminate (C6 & C7 only).
• Fuseholder: Should a speaker fail to switch on when the power switch is
operated the fuse should be inspected. Lift out the fuseholder cover using a
small flat-blade screwdriver, remove the fuse and inspect it for damage. If
required, a spare fuse may be supplied in the body of the fuseholder cover. It
should be stressed however that fuses most often fail only because of a serious
electrical fault.If this is the case then simply replacing the fuse will only result in
another fuse failure.The monitor should be returned to ATC for service if a
second fuse fails.
• Input Socket:The audio signal cable should be connected here. Balanced or
unbalanced cables may be used (See Section 1.3).
Due to the nature of the electronics in ATC active loudspeakers it
is quite normal for a sound to be heard from the speaker when the
power is applied or disconnected.The noise heard will not damage
the speaker and is quite normal.Although ATC uses the highest-
grade components, a different noise may be heard from each
speaker due to slight tolarance variations in the amplifier
components.
1.5 Listening
The ear and brain tend to interpret distorted sound as loudness
and thus underestimate the actual level of undistorted sound.The
C4, C5,C6 and C7,like all ATC monitors, demonstrate very much
lower levels of distortion than conventional systems of a similar
size and it is therefore advisable to begin listening at an artificially
low level and carefully increase the volume. It is also possible for
the C4, C5, C6 or C7 to produce sufficient sound pressure levels
for your ears themselves to become a source of distortion and
make the sound appear harsh.Any audible distortion indicates that
either the system or your ears are being overloaded and that the
volume level should be reduced.
Diagram 2 - balanced cable
Diagram 3 - unbalanced cable
Two Core Screened Cable
3 Pin Male XLR
Connector
3 Pin Female XLR
Connector
To Monitor Input
Hot
Return
Screen
To Source Output
1
2
3
1
2
3
Two Core Screened Cable
3 Pin Male XLR
Connector
Phono (RCA)
Connector
To Monitor Input
Hot
Return
Screen
To Source Output
1
2
3
Centre Speakers