[LAU] Frequency-response analyzer for Linux?

Justin Smith noisesmith at gmail.com
Tue Jul 14 18:25:39 EDT 2009

On Tue, Jul 14, 2009 at 3:05 PM, Ken Restivo<ken at restivo.org> wrote:
> I have a couple DSP-for-dummies questions.
> I'm still intrigued by the idea of getting a proper Auto Wah-Wah sound going.
> I like the approach of building one out of LADSPA plugins.
> My question is this: what tools would I use on Linux to analyze the frequency response and characteristics of the many, many LADSPA filter plugins, so as to decide which has the response closest to a real wah circuit (i.e. a lowpass with a resonant peak just above the rolloff point)?
> What I'm going for is this:
> http://www.geofex.com/Article_Folders/wahpedl/wahped.htm
> I don't know squat about DSP, otherwise I might just try coding something up; the LADSPA spec looks pretty straightforward.
> -ken
> _______________________________________________
> Linux-audio-user mailing list
> Linux-audio-user at lists.linuxaudio.org
> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user

Try running a white noise source through the filter, then look at the
spectral graph output in your favorite spectrum analysis program.
Since white noise should have a flat spectrum, any peaks and valleys
in the output are those of the filter.

More information about the Linux-audio-user mailing list