1176 Knee

I thought I would share my findings after analysing what I believed I was hearing with the 1176s, and what is not specified within the manual…

As you know, sometimes we require softer compression over a wider range and other times harder compression over a narrower range. Of course, this is achieved with threshold and ratio settings but one must also consider the knee of the compressor.

The 1176 does not possess an adjustable knee parameter, like Pro C2 but the knee does get harder the higher the ratio.

For this analysis I adjusted the input of the 1176 at 20:1 ratio so that the source signal was just under the threshold.

20:1

Next, I simply changed the ratio, all other parameters remain the same, most importantly the input gain. The results can therefore only be as a consequence of softer knee settings.

12:1

8:1

4:1

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@Paul, you are the master at testing stuff out! With my limited time in the studio, I really appreciate it. Some times (a lot of the time), I just need a ‘use this to do that, because…’ Thanks mate!!

Thanks Paul! If the VU meter is moving more to the left that means less compression right? I’m having trouble understanding how you realized the knee was changing based. Wouldn’t the change in the VU meter be based on just ratio alone?

Left is more compression. I believed the higher ratios had harder knees; therefore, I set the 1176 to 20:1 and set the input so the signal was just under the threshold, that means no compression and if the knee was the same at all ratios there would also be no compression at any of the ratios but since there is gradually compression the lower the ratio and none of the other parameters have changed the knee must get softer the lower the ratio.

If you had a 12 dB knee, for example, compression would commence 12 dB below the threshold but at a much lower ratio and gradually increase towards the set ratio the closer the signal is to the threshold.

Thanks for the clarification Paul!

here is another very good detailed review of 1176. you may hit google with 1176 (or la2a / whatever) compression curve
http://arpjournal.com/all-buttons-in-an-investigation-into-the-use-of-the-1176-fet-compressor-in-popular-music-production/

and then read this, there is much new information about 1176 and its compression behavior, you cant find that even in the manual…
http://www.uaudio.com/blog/circuit-emulation-software/

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