limiter plugin pre-processing question

[wesimel]

hi - i've been reading up lately on some mastering limiter plugins. it seems like some of these (i've been looking at the sonnox oxford limiter and the psp xenon), have pre-processing stages with adjustable attack and release, and then a second stage to catch any peaks that may pass through the pre-processing stage. it's a little bit more complicated than that (the sonnox has some sort of 'enhancement' slider where you can blend the pre-processed signal in, or something like that).

my question is - i dont see what's gained by having the two different stages. if any peaks not caught by the first stage are limited according to the same process as the pre-processing stage, how would it sound any different if i just set everything to be caught in the pre-processing stage?

does this make sense?

http://www.sonnoxplugins.com/pub/plugin ... -large.htm

[farview]

The pre-processing stage is not a limiter, or at least not the same kind that the end stage limiter is. It sounds more like an inflator, a processor that brings up lower level stuff without changing the peak level.

The idea behind that is to get the level up without clipping off the peaks or making it sound smashed. Once that is done, you don't have to limit as hard, so the whole thing sounds more natural. It's the same idea as using a couple compressors in a row, one set slow to ride the overall level and the other set fast to catch just the stuff that is really out of hand. If done right, you can actually reel in a lot of dynamic range without the audio sounding compressed.

[mrc]

Here's a video you can watch of using an LA2A and 1176 together: http://www.uaudio.com/store/compressors ... la-2a.html

I like the Slate FX-G for a final.