[sdiy] Karplus-Strong overblowing?

[Jonatan Liljedahl]

Overblowing excites the harmonics, so it's the harmonic series, integer
multiples of the fundamental, not the octaves only. Just like flageolettes
on a string instrument.

Allt gott :)
/Jonatan
http://kymatica.com


sön 4 jan. 2026 kl. 15:04 skrev Mattias Rickardsson <mr at analogue.org>:

> Richie  -  Good points about the need of nonlinearities and the advice
> about Waveguide Digital Networks.
>
> Overblowing should result in octaving behaviors, right? Then it's not
> enough to suppress the fundamental, but all the odd partials should get
> weaker and the even ones (the next octave) get stronger. Some nonlinearity
> then needs to favor the even ones.
>
> /mr
>
>
>
>
> Den lör 3 jan. 2026 13:48 <rburnett at richieburnett.co.uk> skrev:
>
>> The original KS model is very basic as others have said. It really just
>> models a single "round trip" delay with some (frequency-selective)
>> damping and possibly some dispersion in the loop. That's fine for
>> modelling things that are struck or plucked with transients like
>> strings.
>>
>> I believe wind instruments are more accurately modelled by Waveguide
>> Digital Networks. These are networks of bi-directional delay lines
>> coupled together by "scattering junctions." The scattering junctions or
>> nodes determine how much of the output of one delay line couples into
>> the next, how much reflects back into the original delay line
>> (propogating in the opposite direction,) and how much is absorbed (lost
>> to heat, radiated, whatever.)
>>
>> Then at the ends of the model you have non-linearities that control how
>> the pressure waves interact with the Reed and blowing pressure at the
>> blown end of the instrument, and the outside air pressure at the, erm,
>> bell end ;-))
>>
>> I think its these non-linearities at the ends that will be critical for
>> modelling overblown behaviour.  The overall model must be non-linear if
>> the behaviour changes when the amplitude of the excitation changes.
>> Otherwise the strongly blown sound wound just be a louder, but otherwise
>> identical, version of the softly blown sound. There wouldn't be a shift
>> to a different resonant mode when over-excited.
>>
>> Waveguide Digital Networks and physical modelling aren't really my
>> thing, so i wont say any more as could be misleading or plain wrong. I'd
>> do some reading of the physical modelling literature by Julius Orion
>> Smith if you're into the theory. Or alternatively string together some
>> delay lines and play about with scattering nodes, filters and
>> non-linearities at the ends if you're into the practical/coding side.
>> "Reed tables" appear to be one way to model the non-linear behaviour of
>> the reed to pressure differences.
>>
>> I hope this is some help. Interested to read other's comments and
>> suggestions.
>>
>> -Richie,
>>
>>
>> >>> Am 02.01.26 um 10:56 schrieb cheater cheater via Synth-diy:
>> >>>> Does Karplus-Strong synthesis allow for overblowing? Are there any
>> >>>> modifications to it that allow it?
>> >>>>
>> >>>> Overblowing is when you blow into a reed instrument too hard and
>> >>>> essentially the fundamental becomes much weaker and the higher
>> >>>> partials become much stronger, kind of "overdriven".
>> >>>>
>> >>>> Thanks
>> >>
>> >>
>> >> ________________________________________________________
>> >> This is the Synth-diy mailing list
>> >> Submit email to: Synth-diy at synth-diy.org
>> >> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> >> Check your settings at:
>> >> https://synth-diy.org/mailman/listinfo/synth-diy
>> >> Selling or trading? Use marketplace at synth-diy.org
>> >
>> >
>> > ________________________________________________________
>> > This is the Synth-diy mailing list
>> > Submit email to: Synth-diy at synth-diy.org
>> > View archive at: https://synth-diy.org/pipermail/synth-diy/
>> > Check your settings at:
>> > https://synth-diy.org/mailman/listinfo/synth-diy
>> > Selling or trading? Use marketplace at synth-diy.org
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260105/4d3ef204/attachment.htm>