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. Ciao, -- FA _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
