There are always a few tell tale signs that audiophiles can pick out. In an analog mix, you should never expect two instruments to share a quantization... But t

There are always a few tell tale signs that audiophiles can pick out. In an analog mix, you should never expect two instruments to share a quantization... But that's what you hear with compression. The cymbal quantization is dependent on the guitar line and the tom/kick bleeds into the bass drum. The attack of the bass bleeds into the guitar, etc. If compressors had access to the raw channels, this is not so much a problem - you can keep each band stable. But they don't, they operate on the frequency domain of the entire mix.