[LAU] Frequency-response analyzer for Linux?

Sampo Savolainen v2 at iki.fi
Wed Jul 15 04:06:29 EDT 2009

Quoting "Ken Restivo" <ken at restivo.org>:

> 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)?

Japa is a good choice. You can also try out the new feature in the  
upcoming plugin frequency analysis feature in Ardour 3.  3.0 is not  
stable yet, but this feature should work good enough for you to choose  
your plugins.

The feature is available in the plugin editor window and shows both  
intensity and phase response of the plugin. The analysis analyses the  
plugin by both running impulses through it and by comparing the actual  
input and output of the plugin in use. For the latter you need some  
real audio feeding through the plugin (put some audio on the track and  
start the transport).

(note. do not try to open old sessions with 3.0! it doesn't work yet  
and could screw up your session)


More information about the Linux-audio-user mailing list