[Stk] Wah-wah filter?

[Robert Oschler]

Hello Perry,

Will you be posting the results?

Robert

On Sun, Oct 6, 2013 at 2:48 PM, Perry Cook <prc at cs.princeton.edu> wrote:
> I especially like the end result of Julius' experiments
> with his CryBaby:
>
> The estimated Q values printed at the end are
> Q = [9.4, 4.0, 1.9],
>
> and the estimated pole frequencies are
> fp = [464, 838, 2252] Hz.
>
> This, plus other data from that article, pretty much
> sets you up to use a 2pole resonator, and just interpolate
> between (and beyond) those values.
>
> Think ill code this up in ChucK this afternoon!!
>
> Prc
>
>
> Sent from my iPad :-)
>
> On Oct 5, 2013, at 7:32 AM, Stephen Sinclair <sinclair at music.mcgill.ca>
> wrote:
>
> On Sat, Oct 5, 2013 at 1:23 AM, Robert Oschler <robert.oschler at gmail.com>
> wrote:
>
> Hello all,
>
>
> I'm a veteran C++ programmer but I am brand new to the STK.  Although
>
> somewhat math challenged I do know basic DSP principles.  Is there a
>
> built-in effect that creates a good Wah-Wah pedal effect?  If so,
>
> where do I start poking around to use it?  If not, are there some
>
> low-level filter effects I can use to build one?  Or do I have to go
>
> it alone and create a separate block of code that does the DSP
>
> operations necessary to create the Wah effect?:  Note, need it to be
>
> fast enough for real-time processing.
>
>
> http://en.wikipedia.org/wiki/Wah-wah_pedal
>
>
> For the guitarists out there, I want to create a truly solid Wah
>
> effect that really sounds like a mouth opening and closing around the
>
> sound, something with some body to it, instead of an adjustable cutoff
>
> filter that sounds more like someone simply twisting the Treble knob
>
> on a stereo (is there some resonance processing involved with
>
> achieving an enhanced Wah effect?).  I'm going to use the effect to
>
> process the sound output of my current STK waveform output.
>
>
>
> Hi Robert,
>
> So there's a bit of work out there on wah wah pedal modeling if you
> search google scholar.  One that jumps out is Julius Smith's work
> which specifically shows how to emulate the Cry Baby pedal, perhaps
> it's of interest:
>
> https://ccrma.stanford.edu/realsimple/faust_strings/faust_strings.pdf
>
> In general (if i understand correctly) a wah wah pedal *is* just a
> resonant low pass filter.  You might be able to use STK's TwoPole
> class to implement it.
>
> Not sure if that answers your question though, since I don't know
> exactly what you mean by "something with some body to it."  (Not a
> guitarist.)
>
> By the way if you just want some good guitar effects and don't want to
> implement it yourself I suggest checking out Guitarix:
> http://guitarix.sourceforge.net/
>
>
> Steve
>
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-- 
Thanks,
Robert Oschler
Twitter -> http://twitter.com/roschler
http://www.RobotsRule.com/
http://www.Robodance.com/