[PD] How to make a buzz? (I'm no king bee)

[Pierre Massat]

It doesn't seem to output a steady pulse either (see attached patch - then
again i hope i got you). Maybe it doesn't really matter. I can try with my
guitar right now.
Out of curiosity, what kind of resonator can i use? I only know resonant
filters (like the moog~ bp filter) and karplus-strong resonators.
Thanks again for your help.
(I think i've been forgetting  to reply to the list...)

2010/9/30 Pierre Massat <pimassat at gmail.com>

> So basically, i get a square wave. Then i use the rzero filter with a
> parameter set to 1, so that i get X(n)-X(n-1), which is equal to 0 all over
> the flat sections of the wave (except for the first sample), and equal to
> Delta (or something) or -Delta at the points where is rises and falls. If i
> clip this again between 0 and 1, i get a pulse everytime the wave rises from
> -1 to 1. Am i wrong? I have never used such a filter...
> Thank you!
>
> Pierre
>
> 2010/9/30 Andy Farnell <padawan12 at obiwannabe.co.uk>
>
>
>>
>>
>> Yeah its a bitch actually because in Pd
>> the blocksize sets an effective resolution
>> for events. You could ask on-list about
>> tricks with blocksize, Frank might have
>> a solution.
>>
>>
>> I'll share a couple of DSP tricks wit you
>> as used in guitar subharmonic processors,
>> if you don't mind keeping it all in the audio
>> domain (which can be more tricky)
>>
>> Firstly you amplify by about 100 and clip
>> the signal
>>
>> [*~ 100]
>> |
>> [clip~ -1 1]
>>
>> this gives you basically a square wave
>>
>> Next differentiate using a [rzero~]
>> so that you get a series of pulses.
>>
>> Rectify them by clipping again [clip~ 0 1]
>>
>> Use these pulses to drive into a bank of
>> parallel resonators for the rattle effect.
>>
>> cheers,
>>
>> Andy
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> On Thu, 30 Sep 2010 20:15:15 +0200
>> Pierre Massat <pimassat at gmail.com> wrote:
>>
>> > Ok, i think i get it.
>> > I've tried do make a simple zero-crossing detection patch using
>> threshold~,
>> > but it doesn't seem to really work. From what i've read here and there
>> about
>> > zero crossing in Pd it seems like the size of audio blocks is an issue
>> here.
>> > Using a simple osc~ as a sound generator and a threshold~ set to 0 0 0
>> 0, i
>> > get a fairly steady bang at very low frequencies, but it gets extremely
>> > messy for frequencies above 10 Hz or so.
>> > I ve tried reducing the block size in the subpatch where threshold~ is,
>> to
>> > no avail.
>> > I haven't found anything that properly deals with zero crossing
>> detection in
>> > Pd. So i'm kinda stuck!
>> >
>> > Pierre
>> >
>> > 2010/9/29 Andy Farnell <padawan12 at obiwannabe.co.uk>
>> >
>> > > On Wed, 29 Sep 2010 08:42:28 +0200
>> > > Pierre Massat <pimassat at gmail.com> wrote:
>> > >
>> > > > Hi Andy,
>> > > > Are you talking about something like that:
>> > > > http://www.complexity.org.au/ci/vol01/fletch01/html/
>> > >
>> > > Not quite. THis is very interesting (I've bookmarked it
>> > > for future reading) but deals with non-linearity
>> > > in a continuous equation.
>> > >
>> > > For rattling, we are interested in dis-continuous
>> > > coupling.
>> > >
>> > >
>> > > > I m not familiar with zero crossing detection at all. From what i ve
>> read
>> > > in
>> > > > the archives it seems to be possible to do it with edge~.
>> > >
>> > > If you search you will find other ways using snapshot~ and threshold~
>> > > too.
>> > >
>> > > > So i'd need to
>> > > > trigger something like a pulsed noise everytime it detects a zero?
>> That'd
>> > > be
>> > > > the trick?
>> > >
>> > > Yes, basically drive another synth that makes a pulse or resonant
>> click
>> > > every time the string crosses zero.
>> > >
>> > > > Thanks again for your help!
>> > > >
>> > > > Pierre
>> > > >
>> > > > 2010/9/28 Andy Farnell <padawan12 at obiwannabe.co.uk>
>> > > >
>> > > > >
>> > > > >
>> > > > > Aha! This is a different problem. It's about creating
>> > > > > a discontinuity such that the string excursion seems to
>> > > > > cause a point of new impact in a different system.
>> > > > >
>> > > > >
>> > > > > The traditional way is to do zero crossing detection
>> > > > > and use that to trigger some other sound.
>> > > > >
>> > > > > best,
>> > > > > Andy
>> > > > >
>> > > > > On Tue, 28 Sep 2010 13:07:49 +0200
>> > > > > Pierre Massat <pimassat at gmail.com> wrote:
>> > > > >
>> > > > > > So i'm really only interested in modeling the rattling sound,
>> the
>> > > buzz,
>> > > > > to
>> > > > > > get a dirtier sound, like in most african instruments. I don't
>> know
>> > > if
>> > > > > > you've ever played a guitar with a strip a paper kind of weaved
>> > > accross
>> > > > > the
>> > > > >
>> > > > > --
>> > > > > Andy Farnell <padawan12 at obiwannabe.co.uk>
>> > > > >
>> > >
>> > >
>> > > --
>> > > Andy Farnell <padawan12 at obiwannabe.co.uk>
>> > >
>>
>>
>> --
>> Andy Farnell <padawan12 at obiwannabe.co.uk>
>>
>
>
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