Quadcomp ®II Owner's Manual v 3.3 CE ©2006 ARX® Quadcomp ®II Owner's Manual v 3.3 CE ©2006 ARX®63
Quadcomp is a Registered Trade Mark ® of ARX Systems Pty Ltd.
gives soft knee transfer characteristics at low to medium compression,
changing to hard knee around 8:1. This gives virtually inaudible subtle
compression where needed, but maximum output before limiting when
used as an overall level controller.
Where to use the Quadcomp II
The QuadcompII gives you 4 independent compressor/limiters, each of
which can be inserted virtually anywhere in the line level audio path.
However, it is not designed to have a microphone or an instrument plugged
directly into it.
Popular uses are: As a desk insert on four channels; on four subgroups; on
the Left and Right console sends AND on two channels, maybe lead vocal
and Kick drum or Bass; as Pre or Post House EQ limiters, as limiters on the
outputs of crossovers, both main and monitor; on four sends of a monitor
desk; the list goes on. We think you’ll find the QuadcompII an invaluable
audio tool.
Application Notes - Sidechain Insert
On each channel of the QuadcompII there is an extra jack socket, coloured
RED, and marked SIDECHAIN INSERT. This jack socket is a Tip Ring
Sleeve type, wired Tip IN, Ring OUT, Sleeve EARTH/GROUND. This
Sidechain Insert is an access point for the control circuitry of the compres-
sor. By modifying the audio signal via this point you can change the way
the compressor ‘hears’ signals, and, consequently, the way it reacts to them.
The most popular use of this feature is as a ‘de-esser’; in other words, a
device to remove excess sibilance ( a “SSSSSSS” sound).
To set this up you’ll need an IN/OUT pair of leads wired to a stereo jack
plug, and an equalizer, either parametric or graphic. Plug the stereo jack
into the Sidechain Insert, and the OUT lead from there to the Input of the
EQ, and the IN lead to the Output of the EQ. Now you’re wired into the
Quadcomp’s sidechain.
Sibilance usually occurs in the 4 KHz to 8 KHz range, so if you push up the
6 KHz slider by 3 dB, you increase the threshold sensitivity of the Quad-
comp by 3 dB relative to 6 KHz. In other words you make the compressor
more sensitive to 6 KHz. Sounds complicated, but sit down with a micro-
phone, mixing console and this set up and you’ll soon hear what we’re
talking about.
For best results this technique should be used as a desk channel insert, so
that you only affect the excess sibilance in a particular vocal line.
As with anything new, some time spent experimenting will prove invalua-
ble. Frequency sensitive compression, as all this is called, has many audio
applications, so just experiment and see which ones work for you.
Introduction
Thank you for choosing this ARX Quadcomp®II. We hope you enjoy using
it as much as we enjoyed creating it. As with all ARX equipment, it has
undergone extensive alignment and ‘burn in’ before shipping. To ensure
continued trouble free use, please familiarise yourself with the contents of
this manual before using.
About the Quadcomp® II
The sheer amount of effects and signal processors necessary for today’s
standards of audio production puts a great strain on the available space in
equipment racks, both in the studio and on the road.
To put it in a nutshell, space is money.
Recognising this fact, ARX design engineers have developed the Quad-
compII, a Four channel Compressor/Limiter in a single rack unit. This
unique and versatile signal processor gives no less than Four independent
channels of precise audio control in the space normally taken up by a single
channel unit.
Despite its compact size, the QuadcompII is not short of features. Each
channel has an IN/OUT switch, individual controls for Threshold, Ratio and
Output, and a 7 LED gain reduction meter display. In addition to this, as on
all ARX single rack unit equipment, there is a numbered marker panel that
you can write on for easy confirmation of your compressor assigns.
All Inputs and Outputs are electronically balanced on XLR connectors, and
full access to each compressor sidechain is provided through insert points
on the rear panel.
Channels 1 and 2, and channels 3 and 4 also feature a stereo link switch,
located on the rear panel. When switched IN, Channel 3 becomes the master
and controls all the functions of Channel 4 except Output gain. LED indica-
tors on the front panel confirm these settings.
