Really? I find that very strange. I've ∗always∗ approached synthesis with
the harmonic spectrum in mind. The waveform is the ∗result∗ of the sound's
harmonic content. When you're creating sounds, isn't it better to think in
terms of the harmonic alterations rather than the shape of the wave? When
applying a lowpass filter, for instance, I imagine it as something like a
window-shade closing down on the spectrum, not as rounding off the peaks of
a sharp waveform. The ear hears the spectrum, not the oscilloscope image.
Also, additive synthesis and Fourier analysis predate digital by a pretty
good margin. These were terms that we used to discuss in the old analog days
long before the first digital synthesizers hit the market. While I agree
that additive synthesis is probably easier to implement in digital, I don't
think it's at odds with analog at all. That's why we use more than one VCO!
I agree that waveform manipulation is easier in analog, and I think that the
discussions of waveform shapers, folders, and multipliers can be very
fruitful. But as a generalization, they still only affect the amplitudes of
the existing harmonics (I usually use the term "partials" because it was
beaten into me that the Fundamental is not a harmonic, so when you want to
refer to ∗all∗ of the Fourier components, including the fundamental, you
need to use 'partial' rather than 'harmonic.' Although in recent years it
seems that the misuse of the terminology is getting ingrained into the
language, the same way that "font" is used to mean "typeface" when that's
not proper either).
Know what I mean though? After the fundamental, the harmonics in simple
waveforms are specified as period-times-1/2 (octave, or first harmonic),
times-1/3 (octave-fifth, or second harmonic), times-1/4 (two octaves, or
third harmonic, etc.). You can filter this, waveshape it, and so on but you
still aren't changing these relationships unless you run the signal through
a ring modulator. The fact that these relationships are 'set in stone' while
so many other aspects of the sound are open to us for manipulation ...
∗bugs∗ me :) .
The reason this kinda thing keeps me up at night is because I'm interested
in microtonal music. Our musical scale closely parallels the harmonic series
of simple waveforms like we've been talking about (at least until you get up
in the range where the compromises of equal temperament cause a divergence).
When you look at the unusual scales of other cultures, like the music of the
gamelan, they aren't just playing weird tunings with Western
instruments---their instruments produce tones with harmonics that echo and
fall in line with their scales, just as ours does. We have instruments that
produce "simple waveforms" (please allow me that ridiculous statement) that
work with our equal tempered scale, and they have instruments that have
complex tones and scales to match them.
I find this whole thing very interesting. I'd love to play with those
relationships. Sure, digital's always an option, but I want to do it with
patchcords and knobs! Typing on a keyboard to specify harmonics is for the
birds.
-----Original Message-----
From:
jwbarlow@... [mailto:
jwbarlow@...]
Sent:Tuesday, 21 March, 2000 10:40 PM
To:
motm@onelist.comSubject:Re: [motm] Modules for Pushing Partials Around
I think viewing waveforms as a composite of harmonics lends itself much more
to digital (through Fourier analysis). It seems that when you view a sound
as a waveform you are more "in tune" with the basic ""philosophy"" of
"analog synthesis." As such, I think a more easily solvable engineering
problem would involve manipulating the waveform in unconventional ways.