5 Oct
2006
5 Oct
'06
6:46 a.m.
On Wed, Oct 04, 2006 at 10:51:08PM -0500, Andres Cabrera wrote:
I've written a paper analyzing the characteristics
of some software
dynamic range compressors. The interesting part concerning linux, is
that all my results show jaggedness on the gain reduction curves. I did
the tests using Ardour, Audacity and Rezound with the same results,
which points to something strange in some part of the process.
Or in your measurement methods which are ill-defined, making it all but
impossible to correctly interpret some of the results.
- How do you measure gain ? By comparing single input/output samples ?
It seems so, otherwise how do you obtain a gain vs. time curve at
50 Hz with sub-millisecond resolution (Fig. 3) ?
This will be invalid in many cases, for example if the plugin includes
audio delay to achieve 'zero latency', as you suggest some of them do.
- This delay is the first thing that should be measured. Without
this information it is impossible to evaluate the results.
- How on earth do can you define the level of a white noise signal
by a peak value ?
- What is a square wave at 0dB FS ? Positive and negative samples
at the maximum amplitude ? That does no correspond to a analog
square wave signal.
- How do you expect to measure distortion using square waves ?
--
FA
Lascia la spina, cogli la rosa.