Software vs. Hardware Compressors

[gsilbers]

Cool topic that started in dance mastering and i thought putting it a new thread.

here it is
ME:
you also mentioned somewhere , or hint at , staying away from software compressors. is that because of the harmonic dist. that is added with analog compressors which gives a better sound, or is there something else about software comp?

from Bob Katz
Someday I suspect software compressors will be able to produce the identical sound that we can get from an analog compressor. That day is fast approaching. In the meantime, be cautious. Some of the software emulations seem to distort in a ugly way far earlier than their analog counterparts when you start to use more gain reduction and aggressive time constants (fairly fast release). Some of this is aliasing distortion, if the software compressor does not double or triple or quadruple-sample, or if you are not running at double sample rate. Some of this I think is lack of expertise of the software designer at emulating the characteristics of the RC circuits on the analog side. And some of it may be my fault, inabilty to work by the numbers when I'm trying to get a tricky sound! I think I have the numbers down pat when I'm just trying to subtly enhance something that was mixed well. What separates the men from the boys is the ability to enhance something that was not mixed well but you know can be enhanced with "attitude". That is, the "ultimate mix bus compressor" that the client did not have.

When it comes to "optical" (which is usually gentle and not used for "attitude") I know that great strides have been made at emulating the speed with which an optical compressor returns to unity gain after it's been pushed, and I've heard some very nice optical emuations from PSP and from Waves in the Ren comp. In fact, I'm prepared to say that you can do optical pretty darn well now with the PSP and get a very "warm" sound quite easily now, at least at 96 kHz.

But the more aggressive sounds that you can get from an API or a Cranesong Trakker, I've not heard done as well, I start to hear grunge from the digital versions. They seem to "choke up" earlier than their analog counterparts. And it's a lot harder to keep them "warm and fat" in the aggressive modes, especially faster release times.

Some of my counterparts say the Weiss DS1-MK2 can do punchy and fat just as well as an analog unit, but I have not been able to make it do so, even though I use it for other stuff all the time and I own TWO Weiss units! I do have to try though, in theory, it's all time constants, and it's certainly a very low distortion digital circuit with (theoretically) as fast or slow a reaction time as anyone could want. Same with my TC Electronic System 6000. I have to spend a day with it and shoot it out against the Trakker really trying to get "that sound".

I guess it's because when I'm looking for aggressive, for an "attitude", for hip hop or rock, with only a few minutes time I can get "the sound" quickly with the Trakker, and not hear any ugliness. But I really have to coax it out of the digital versions and I'm not entirely sure if I've found it or fooling myself. Stay tuned on this. It may be possible with the TC or the Weiss and I may not have found the formula. But i'm pretty convinced "aggressive" can't be done with any of the current plugins. I could be proved wrong on that![/quote]