[linux-audio-dev] Paper on dynamic range compression

[John Rigg]

On Tue, Oct 17, 2006 at 11:56:20AM +0200, Fons Adriaensen wrote:
> On Mon, Oct 16, 2006 at 07:48:35PM +0100, Dan Mills wrote:
> > The gain control signal has energy right the way out
> > to the band limit (and probably aliased around it),
> > never mind what happens when that hits the multiplier!
> 
> The question is: how much of this HF energy is there ?
> There shouldn't be much in a compressor with controlled
> attack / release times. In that case it is always possible
> to filter the control signal. In fact the obvious way to set
> attack / release times is by such filtering !

True, but if the audio signal contains significant HF energy near
the band limit, it doesn't take a very fast gain change to push it
past that. Bear in mind that the ear is _very_ sensitive to aliasing
artifacts, so `significant' can be a very small amount.

John