> > I don't know what Bob Katz has to say, but I'll > assume he's talking about good old parallel compression > that's been around for decades where you have > two parallel signal paths: one without compression > and one with (and then they're combined). Bob Katz's version of upward compression - aka parallel compression - is more than just multing a track and adding compression - there are specific, unusual, settings on the parallel compressor- you use as low a threshold as possible and a very fast attack- basically removing the transients from the compressed version but emphasizing the quiet parts(cymbals decays, reverb tails,etc). once added back to the signal it increases the quite parts without destroying the transients- which are still in the original path. This is much more transparent than squashing the transients in order to bring up the whole signal(normal compression with makeup gain). Typical, downward, compression makes the loud parts softer. Parallel, upward, compression makes the soft parts louder. -Loudon