[Csnd] compress2: general relations between parameters and usual compressor settings

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1

Hey hey,
I've been working with compress2 lately, but I have difficulties understanding the relationship between its parameters and typical compressors.

The attack, release and look-ahead times and the ratio are clear enough. But how about the low and high knee and threshhold?

The average compressor plugin has the knee hidden inside it and offers a threshhold, which is apparently not the same as compress2's threshhold, but rather more related to the knee values. I think.

Coming from Linux, I think of the Invada studio compressor, which offers
the following:
tight/sloppy: which is of no interest
Attack: kAtt in compress2
Release: kRel in compress2
Threshhold in dB: ?
Ratio: kRatio im compress2
Gain dB: a makeup gain, applied afterwards
Soft clip: of no interest here
Other compressor plugins offer similar controls, some adding a knee
radius or one value knee setting, others can set a look-ahead time.

Can someone give me a little guidance? An article that explains the relationships between these settings would be good enough.

Best wishes and thanks,

Jeanette

2

Hi Jeanette,

Your assumptions about threshold, low-knee and high-knee are correct.

Threshold in compress2 is not how it would be understood in a generic compressor; it is the threshold of a separate noise gate. The threshold, as it would be understood in a generic compressor, is the mid point between low-knee and high-knee. Therefore, if low-knee is -40 dB and high-knee is -30 dB, the compressor threshold is -35 dB. Some implementations offer a control over knee size, which in this example would be 10 dB.

I hope this is correct!
Iain

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3

Hi Iain,
many thanks! This makes sense and would be very easy to work with.

Best wishes,

Jeanette

Dec 18 2024, Iain McCurdy has written: