ok I now I tried a crude and quick multiresolution FFT analysis at log 2
basis and it seems to work.
However my partial and transient tracking does not work naymore on the
higher bands since there is too much modulation from the windows now,
but it seems that in general this is the direction
Maybe you could make the analysis with a filterbank, and do the
resynthesis with FFT?
Years ago I made such a synth based on "analog" Fourier Transforms,
(the signal is modulated and rotated down to 0 Frequency and that
frequencies around DC are lowpass filtered
depending on the bandwitdh
Am 04.11.2018 um 03:03 schrieb Theo Verelst:
It might help to understand why in this case you'd chose for the
computation according to a IFFT scheme for synthesis. Is it for
complimentary processing steps, efficiency, because you have data that
fits the practical method in terms of
It's a complicated subject when you fill in all the boundary conditions
properly, isn't it?
Lots of frequency considerations look a bit alike but aren't mathematically
equivalent.
The human (and animal I suppose) hearing is very sensitive to a lot of these issues in all
kinds of convoluted
as I wrote before, it depends on the phase angle whether or not the
amplitudes add up when you add the numbers
with opposite phase, and equal amplitude, the amplitudes cancel, with
same phase they add up,
with pi radians it is sqrt(2), ect,
but I made a quick hack test and it doesn't
[resending, I think I accidentally replied off-list]
On 1/11/2018 5:00 AM, gm wrote:
> My question rephrased:
> Lets assume a spectrum of size N, can you create a meaningfull
spectrum of size N/2
> by simply adding every other bin together?
>
> Neglecting the artefacts of the forward
.
for a sufficiently small window, it will be a single sinusoid, but the
amplitude will vary in adjacent windows.
that's my spin on the issue.
r b-j
Original Message --------
Subject: Re: [music-dsp] two fundamental questions Re: FFT for realti
An I think you can model them simply by adding their phasors/bins/numbers...
for opposite angles they will cancel, for the same angle they will be
amplified
so the model is correct at the center of the window, but it models just
an instance in time and spreads this instance
in this way
On 3/11/2018 3:41 AM, Ethan Fenn wrote:
No length of FFT will distinguish between a mixture of these sine waves
and a single amplitude-modulated one, because they're mathematically
identitical! Specifically:
sin(440t) + sin(441t) = 2*cos(0.5t)*sin(440.5t)
So the question isn't whether an
>
> In any case, most signals are not sums of stationary sinusoids. And since
> signals are typically buried in noise, or superimposed on top of each
> other, so the problem is not well posed. For two very simple examples:
> consider two stable sine waves at 440Hz and 441Hz -- you will need a very
Thanks for your time
My question rephrased:
Lets assume a spectrum of size N, can you create a meaningfull spectrum
of size N/2
by simply adding every other bin together?
Neglecting the artefacts of the forward transform, lets say an
artificial spectrum
(or a spectrum after peak picking
Hi,
Sorry, late to the party and unable to read the backlog, but:
The "FFT^-1" technique that Robert mentions is from a paper by Rodet and
Depalle that I can't find right now. It's widely cited in the literature
as "FFT^-1"
That paper only deals with steady-state sinusoids however. It won't
--- Original Message --------
Subject: [music-dsp] two fundamental questions Re: FFT for realtime
synthesis?
From: "gm"
Date: Tue, October 30, 2018 8:17 pm
To: music-dsp@music.columbia.edu
--
Original Message
Subject: [music-dsp] two fundamental questions Re: FFT for realtime synthesis?
From: "gm"
Date: Tue, October 30, 2018 8:17 pm
To: music-dsp@music.co
Am 30.10.2018 um 16:30 schrieb gm:
-Compress the peaks (without the surrounding regions) and noise into
smaller spectra.
(but how? - can you simply add those that fall into the same bins?)
snip...
I am curious about the spectrum compression part, would this work and
if not why not?
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