How important is it to oversample if for example you are just using a clean compressor and doing like 2-4db gain reduction? Do you feel like you should oversample all compression or is it only necessary when doing deep compression with lots of gain reduction?

Thanks!

(trying to get an overall cleaner sound on my next batch of recordings, don't want to overdo it though at the expense of unnecessary wasted cpu and long rendering times etc... trying to find a balance here between a clean sound, and being able to get stuff done quickly (and at zero latency whenever possible))

I'd say, in a word, no. That's not much GR.

With such small reduction, maybe you don't need a compressor at all.

Too radical, ok, maybe you need 5-10 compressors (buy them all) in series doing .5dB GR each with 8X oversampling.

Maybe you just need a clean limiter - with infinite oversampling, of course. Don't worry about the latency - that's your great great grand kids kid's problem.

You don't have to feel anything else, just listen . In DC8C for example, it has no benefit, just maybe very tiny benefit when doing "clean compression" with high threshold. In another compressor, it may affect more. There's a very "clean" sounding compressor that does extensive oversampling (not selectable), but you wouldn't like its 2122 samples long latency .

Which one is that?

SplitComp

oversampling doesn't even have much of an effect until you start to get into major hard-clipping territory.

there are going to be minor differences with high-frequency content but it just isn't that important in the general case.

try for example running a drum loop through a compressor without oversampling. run it at 44.1k, then try it at 192k. can you hear major differences?

i wouldn't expect you could hear any difference.

("general case" doesn't include high frequency synth leads designed to test this kind of issue.)

The only time I use oversampling on the compressor is when the material has "hard-edge". It's almost unnecessary in 99% of compression.

I noticed JCompshaper has oversampling on it. What does it do? (Besides chew up CPU)

A compressor normally has a smooth enough envelope, so hardly any high freq in it. In theory 2x oversampling would be useful (I've seen higher oversampling in some compressors, never understood why), but in practice I never noticed any difference. On the contrary, when used as a limiter it's more a problem.

oversampling is not the answer in this case
well, actually it is an answer but a very weak one ...

if you're using your compressor to hard-compress a signal at -48db with very short attack/release times, oversampling is the answer.

http://soundcloud.com/aciddose/example-hardcompress

with just the kick in there it isn't an issue. you can see the harmonics are generated up to about 30th though. insert some hihats or other high-frequency components like conga or whatever and boom, aliasing madness.

oversampling by 4x to 16x will fix this.

oversampling is not the answer in this case
well, actually it is an answer but a very weak one ...

sure. what other answer would you have then? you're processing an input where the fractional information is not available. do you suggest estimating? the source of the issue is that you're applying a simple non-linear function. what do you suggest to apply when anti-aliasing f(x)=x(2-|x|) ?

oversampling is the most CPU-efficient solution, and it works.

another solution would be "don't do that", the problem is though that some people do.

how much gain reduction there?

-48db. attack = 0.05ms, release = 2.5ms, non-linear application.

the compressor is modeled after a circuit i designed and it works perfectly. any arguments about "wah wah, intermodulation-distortion, blah blah blah" are 100% horseshit.

the distortion and modulation are intentional and desirable. the aliasing is the undesirable component.