On Wed, Jul 06, 2011 at 09:02:46AM +0000, Fons Adriaensen wrote: > On Wed, Jul 06, 2011 at 10:24:02AM +0200, Cedric Roux wrote: > > > > I'm using a four band parametric EQ (ladspa 1970) and am wondering > > > what > > > manner of units the bandwidth parameter employs. The range is > > > 0.125-8. > > > Octaves? > > > > you're sure about the number? I can't see that plugin at: > > http://plugin.org.uk/faq.php > > It's one of mine, and none of them (1941..1980) is on that list. > Don't ask me why. > > To answer the original question: the number 1/8...8 is the > relative (to the center frequency) bandwidth, it is a pure > ratio and has no physical dimension. > > It is roughly equal to the difference (in Hz) between the > -3dB points at full positive gain, divided by the center > frequency. > > A filter such as this one has actually two damping factors > in its transfer function, and both can change in function > of the actual gain setting. So there is no single 'obvious' > way to define its bandwidth, you need something pragmatic > such as the definition used here. What would some good starting point be to experiment with this parameter? The plugin states 1 as its default, but nama's mastering chain EQ uses 1/8. Cheers, S.M. _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
