I downloaded this paper

A NEWALGORITHM FOR BANDWIDTH ASSOCIATION IN
BANDWIDTH-ENHANCED ADDITIVE SOUND MODELING

Kelly Fitz, Lippold Haken, and Paul Christensen

http://www.cerlsoundgroup.org/Loris/papers/association.pdf

in PDF & it's quite interesting.


There is no date on the paper, & because its from CERL Sound Group i'm
assuming maybe it's a few years old, & that much of the theory in it has
been implemented in Loris. Alternately, it's a further development on / from
the Loris approach (which i still haven't been able to play around with so
cant give any real verification..)

Anyway, it has some formulas in it that i can't quite get my head around.

The thing that specifically interests me is on page 2, as it describes the
formula used to create bandwidth enhanced partials.

The basic process is modulation of the sine by an interpolating noise
signal, whos frequency is representative of the allocated "bandwidth" (i
think - a familiar approach & one that I illustrated & had verified on this
list...)

But there's some extra trickery involved, & i can't get my head around it,
largely as i'm not familiar with a lot of the maths jargon.

There's some sort of averaging of the residual spectal analysis in proximity
to each of the partials (ok, i can give that a crack..), but how is this
this average converted into a noise weighting for the partial exactly?

I'm thinking of attempting some sort of crude mockup of the process by
averaging the "residual" output from SPEAR analysis / .txt output & applying
it to the partials (also extracted via SPEAR, & that i'm reading in via
GEN23 in individual text files.)

I'm presently using ADSYN to realise, but could convert to individual oscils
in order to provide the bandwidth enhancement.

As the attentive reader may already realise, I am somewhat enamoured with
ratios as the basis of spectral definition as i'm hoping to start
interpolating partial weightings from handfulls of collected samples to
create expressive / dynamic / note sensitive spreads - to create what i am
calling a sort of "resynthesis data matrix" - where any point in the matrix
can be reached from any other point & a smooth transition of the spectrum
from one state to the other is always possible.

Sure, It's quite elaborate & computationally expensive, but hopefully a lot
of what i'm doing might be some eventual basis for some opcode development
(even if eventually i do it myself...), as well as the shorter term aim of
simply getting some complex, expressive, kick arse sounds that never really
sound exactly the same way twice.

I wrote to Kelly Fitz but have heard nothing back yet.

I know Ugur's very maths savvy, but anyone who can help me get my head
around the maths to do a crude mockup of this i'd be very greatful.

cheers

the resident lunatic.






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hermetic music * python * csound * possibly mindless ranting
various werk in perpetual delusions of progress....

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