Add, subtract, multiply, divide, logic operations ...
Christopher_List at Sonymusic.Com
Christopher_List at Sonymusic.Com
Thu Dec 12 18:09:15 CET 1996
> Take the first wave, and center it on 0v
> so that you have a + and a - swing (ie, no bias). Set a sample
frequency,
> say one value for as fast as I can type it, and then you
> may end up with sample points like this:
>
> -3 -3 -2 -2 -1 -1 0 0 +1 +1 +2 +2 +3 +3
>
> Now, the second wave may end up looking like this over the same amount
of time:
>
> -3 -2 -1 0 +1 +2 +3 +2 +1 0 -1 -2 -3 -2
>
> And, if you *add* these points together you'd get:
>
> 0 -1 -1 -2 0 +1 +3 +2 +2 +1 +1 0 0 +1
>
> Which is not the same as hearing two tones an octave apart.
> I think this is what he's looking for...
>
> Mark
This must be that new math. In my book (-3) + (-3) = -6, not 0. What're you
trying to pull here, Pulver? :)
Seriously, though - looks to me like you're just subtracting the values - not
adding them.
As far as I'm concerned, a summing circuit, adds together the voltages at any
point in time.
Period.
If you mathmatically add a sine wave to a sinewave an octave above it, you
hear two sinewaves an octave apart.
Period.
Mixers add voltages - they therefore add sounds. Mathmatically, acousticly,
however you wanna slice it.
When you mix (a.k.a. "add") the voice of, say, William Burroughs with the
sound of, say, a hip hop beat, the fact that you
can still recognize each sound in the mix doesn't mean that the sounds haven't
been modified by adding
them together - they've been modified quite a bit. In fact I would challenge
you to ever get back either of the
original sounds. The sounds have been added together - period.
Although, the mixer circuit in the Autoconfabulator mkII did realtime
frequency inversion before adding the
incoming waveforms - but that was driven by a microprocessor...
- CList
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