Re: [LAU] Frequency-response analyzer for Linux?

On Tue, Jul 14, 2009 at 3:56 PM, Fons Adriaensen<fons(a)kokkinizita.net> wrote: > On Tue, Jul 14, 2009 at 03:25:39PM -0700, Justin Smith wrote: > >> 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. > > For a more 'musical' analysis, use Japa. It has either > a logarithmic or perceptual frequency scale. Pink noise > source is built-in, and if you set the analyser response > to 'Proportional' it will show a flat spectrum for pink > noise. It can also show the difference between two spectra, > e.g. input and output of a filter, and this produces much > more stable displays when using a noise test signal. > > For the filter, you could try on of the four Moog VCF > plugins I wrote years ago. Apart from the resonant > lowpass they will also add some juicy distortion at > high levels, as does the original Moog filter and > probably all real analog Wah processors. Frequency > control is logarithmic, which is probably what you > want, and there are separate control inputs to > set the static frequency and resonance and their > modulation. One problem could be that the modulation > inputs require audio rate signals (the filter were > designed for use in AMS) but that can be changed > easily if you want. If you want to play with them > use AMS. > > But Japa and the filters to be found at > http://www.kokkinizita.net/linuxaudio/downloads > > The filter plugins are in the MCP set. > > -- > FA I used japa years ago, but forgot its name, thanks for this excellent piece of software, which I am excited to have rediscovered.