MOTM

Hhhmmm, why all the oscillators? Couldn't you do the same thing with 8 or 9
and just a handful of multiplexed 'sine was animators'? ;-)

John L Rice

-----Original Message-----
From: motm@yahoogroups.com [mailto:motm@yahoogroups.com] On Behalf Of
Kenneth Elhardt
Sent: Saturday, August 16, 2008 7:05 PM
To: motm@yahoogroups.com
Subject: Re: [motm] Experiment, NOW 27 Sinewaves Synthesize Orchestra

ac writes:
>>FFT?<<

FFT? It's involved in part of the process, but a couple of different methods
could be used.  In theory, that part could even be done by analog
electronics.  But what you're hearing are nothing more than a few sinewave
oscillators.

Jeff Laity writes:
>>The triangle needs work, sounds too synthy.<<

Ha.  If I had a dime for everytime somebody said something real sounded or
looked fake, I'd be very rich.  Just the Seekers synth alone would have made
me a lot of money.  You'll have to blame the most high for the physics of
sound, or the maker of the triangle.  I have no control over that.

Les Mizzell writes:
>>Would you mind further expounding upon exactly what we're hearing?<<

I guess it could somewhat be called a resynthesizer, but instead of using
one oscillator per harmonic, or throwing massive amounts of oscillators and
multi-band noise sources at the problem as everybody else does (and usually
with varied success), I'm using only a handful of sinewave oscillators to
synthesize all the frequencies of the entire audio range.  Since they're
oscillators, and relatively few of them, I can them make them do all kinds
of things really easily.  My main drive to do this was to get virtually
artifact-free pitch shifting of polyphonic audio.  There isn't a single
hardward effects unit on the market that can do that.  If they sound good,
they only handle monophonic audio.  All the others sound like crap.  More
audio demos below.

Here's the same demo, but only using 27 sinewave oscillators to generate all
the sound heard:

http://home.att.net/~elhardt3/27_Sinewaves.mp3

Here's an example of the pitch shifting (while preserving time).  First is
the original audio, followed by it pitched up 3 semitones, then up by 7,
then down by 5, the down by 12.

http://home.att.net/~elhardt3/PitchShiftDemo.mp3

Just for the hell of it, I added strings pitched up an octave at the 19
second mark, and a bit of sub bass at the 31 second mark.

http://home.att.net/~elhardt3/OctaveStrings_SubBass.mp3

My pitch shifter can also do selective pitch shifting where only a certain
frequency range is pitch shifted.  In this case, I took speech synthesizer
which like most on the market have a limited bandwidth, in this case only to
8K Hz, and then shifted up the 4K to 8K range an octave to fill in the
missing 8K to 16K range to get a clearer more hi-fi sound with more
presence.  First is the original low-fi version followed by an extra octave
of pitch shifted sound.

http://home.att.net/~elhardt3/SpeechSynthExtraOctave.mp3

-Elhardt


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