A long time ago, when I was a fresh-faced student of sound engineering, I went to a trade show (in the days
when you had to beg your way in, if you weren't in the business already) and alighted on the stand of a company
who had a new and wonderful compressor to show off. 'Listen to this,' said the silver-tongued salesman. I listened
as he demonstrated his amazing box. 'That's 30dB of compression. Does it sound compressed to you?' I looked at
the gain reduction meter, I listened, I looked at the gain reduction meter, I listened. Sure enough, the meter was
showing a full 30dB of gain reduction and the music I was listening to sounded as fresh as a live performance. I
knew something about compressors, and I knew that 30dB of gain reduction ought to be the sonic equivalent of
what an apple looks like after it has been through a cider press. It's a good thing I didn't have any money or I
might have bought it on the spot.
With the benefit of experience I know what happened. I am sure that it was a reasonably good compressor, but
not significantly better than any other. What the salesman had done was to turn the release control to maximum.
Release, as you know, is the time it takes for gain reduction to return to zero after the signal has passed below
the compression threshold. In this case, the signal never passed below the threshold long enough for the level to
begin to return to normal, to any significant extent. The result was indeed 30dB of gain reduction, but not 30dB of
compression. You don't need a compressor to get any amount of gain reduction - just lower the fader.
Compression implies a constantly changing amount of gain reduction, and the gain reduction meter must be visibly
dancing up and down. If it is not, you're wasting your time. How fast it dances up and down is up to you but, if
you want value-for-money compression, a short release time will give you a more audible compression effect
(Figure 1). A longer release will lessen the audibility of the compression, but you won't actually get as much real