[bob katz]

[QUOTE=nick_soldier;3892409]I was reading Bob Katz book.
Mastering- The Art and Science.
Regarding Parallel compression to bring up lower levels.
Upward type compression.

He was mentioning a ratio of 2:1 or 2.5:1
I understand the fast attack time, and look-ahead recommended.
But the release times of 200ms- something seem too long to accomplish the goal. Wouldn't faster release times accomplish this goal better?
/QUOTE]

Faster release times can make the sound more "aggressive" but you can easily start to hear pumping in parallel mode. In the second edition I talk about two different approaches to parallel compression. In the "transparent" approach (fastest attack, 2:1 ratio, -50 dBFS threshold, medium release) I've found that too fast a release time can bring up the reverberation in a recording, often very unpleasantly. In the "attitude" approach (medium attack, Medium ratio, Threshold to taste, medium release) I've found that too fast a release time makes the recording sound too compressed and too slow a release makes the recording sound not compressed enough. In the "attitude" approach you have to optimize attack and release times so the GR is moving at a medium rate in time with the rhythm of the music, much as you would manipulate a downward compressor, so there is no such thing as "faster is better" but rather "the right speed gives you the right sound". Hope this helps.

There are VERY few upward (bottoms up) compressors, but by definition and its operation, parallel compression creates an upward compressor. It's just a matter of how you use it that decides whether it's going to operate on the extreme low passages (usually done in transparent compression) or the middle range passages (usually done in attitude compression) where the meat of the music lives. The more you push the gain, the closer the compression gets to the top of the range and begins to sound similar to a downward compressor.

BK