Mackie Stereo and Mono Side chain Compressor User Manual

The Soft Clip switch activates a soft-clip limiter 
circuit. There is also a threshold slider. When 
the output level goes above this threshold, the 
soft-clip circuit kicks in. This circuit starts add-
ing analog-style distortion, which rounds off 
transient peaks, and avoids the harsher sound 
of a straight digital clip. The lower the thresh-
old, the more analog-style distortion is added. If 
the threshold is set too low, you hear this as a 
very crunchy distortion sound. It is best to keep 
the threshold between –3 dB and –1 dB unless 
you are going for a special sound effect.

The Soft Clip LED (next to the slider) activates 
when the signal is above the soft-clip threshold, 
so keep an eye on it.

The soft-clip circuit is the last thing in the sig-
nal processing chain. 

So far, we have just shown the use of the 
threshold and end point controls to set up a 
simple compressor. 

One of the very powerful features of the com-
pressor, is it allows you to draw your own curve 
between the threshold and the end point, and 
really shape that Jello mold. Up to four nodes 
can be added to the curve. This depth of editing 
is helpful in defi ning detailed nuances in your 
curve such as hard knee, soft knee, and expan-
sion.

The fi gure below shows 3 extra nodes – labeled 
1, 2, and 3. These nodes are being used, in 
this case, to essentially draw a knee for the 
compressor curve. This gives a nice smooth 
transition from applying minimal compression 
at low input levels, to much higher compression 
at higher levels.

Nodes can be added to the contour graph by 
right-clicking the mouse on the contour graph. 
Right-clicking on the graph where there is no 
node adds a node, up to a maximum of 4. Right-
clicking on an existing node removes it.

The four numbered nodes always appear in 
order from left to right. You can't add a node be-
tween, for example, nodes 1 and 2, even if they 
are the only nodes active.

You can also add or remove nodes by using the 
Node Edit Selector knob and toggling the Active 
Node switch. Click on the knob and move the 
mouse either vertical or horizontal to rotate it 
and select a node. Use the Active Node switch 
to turn a node on or off. 

The position of a selected node can be adjusted 
by using the Input and Output level sliders. 
These sliders do not appear for the threshold 
and End Point nodes, just nodes 1 to 4.