Anyone reading this who knows what I mean when I say compression, and understands what compressors do*, probably thinks I’m about to say something ridiculous. I have to be careful, and actually the title is a little misleading (but it had to be short).
The point is that compressors reduce the dynamic range of the signal that passes through them, that is true, but that means that elements within the signal are quietened and loudened independently. Music is made of a mixture of elements. So while the dynamic range of the track as a whole is reduced, the dynamic range of elements within the track are increased.
Take the example of a side-chained kick-bass set up. The dynamic range of the bass being increased. This is obvious when you consider a genre like Dubstep, for which brick-wall limiting is an explicit feature to the extent that it’s an effect, the elements within a Dubstep track jump all over the place as the compressor flattens out the spikes. If anything it’s more this extreme movement of gain of the individual elements that really characterises over-the-top limiting than any perception of reduced overall dynamic range.
*I’m not talking about data compression, like mp3 compression… although I’m sure mp3 compression has implications on dynamic range.