my understanding of the original post was that it's still compression, not expansion. but the compression only happens 'below the threshold', which would have to mean that stuff below the thresh is brought up in level, and things above it are left alone, at least that's what i would think that means. i think the idea seems like something that would probably only exist in software, but again i'll say that it would be possible to hand craft a nebula program to do this, although now that i think about it, it would be very tricky. and you would have inverted attacks that fade in instead of peaks that drop as compression kicks in.
Thanks for thinking about this (compression below the threshold) maybe not something that happens 'naturally' in most audio hardware. And even maybe it's not even called the same thing (upward compression), or accidentally occurs as a side effect in some hardware... more on this down the road maybe.
You're talking about good ole expander/gates & compressors capable of negative ratios.
For positive ratios a "Compressor" lowers dynamics above a threshold. Negative ratios will increase what's below. A "Expander" Increases dynamics above a threshold. Or lowers the level below the threshold depending how you want to look at it. Expanders are used very often for vocal tasks. They used to be must have in the days of tape to avoid noise/hiss build up. I have a few I could sample if there is a demand. D*x 903 & 904 (the best IMHO), & a N**e 8801.
Last edited by rhythminmind on Tue Aug 20, 2013 5:04 pm, edited 3 times in total.
I think that upward compression, as described by the op, is not likely to work well in Nebula because you need extremely short attack times. It's a very transparent way of reducing dynamics without killing the peaks, but doesn't always work well- for instance when your source material is a bit noisy to begin with.
Upward compression doesn't increase the dynamic of the signal, but decreases it, like regular compression, and thus can't be compared to expanders. If you're looking however for a way to increase dynamics, there is the KultComp, which features De-Compression (Increases the level of signals above the threshold instead of decreasing it like a regular compressor).
Thanks again for all the coments! I really wanted to get 'upward compression' under my control using some of the software plugs I mentioned earlier in an effort to be able to compare the sound and maybe even explain it in hopes a Nebula preset might perform the task. I'm really havin problems controlling it however and, as I mentioned in another forum, the easiest way for me to get to the sweet spot is thru 'parallel [downward] compression' that was mentioned earlier. It's just so darn easy & fast on my re-masters (master bus), so in the Nebula world I'm grateful to Mr. Cupwise for putting the 'Dry' slider on his recent compressors which gets me most of the way there (closest to the wet/dry knob) without having to break out another route in parallel and 'hope' there aren't any phasing issues in addition to the minor workflow issue.