Add, subtract, multiply, divide, logic operations ...

[Mark Pulver]

>    > 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.

Ya' know... I can't tell you how many times I looked at those numbers and
tried to (extrapolate and) visualize the resulting waveform. When I saw the
weird spikes happening... It didn't make sense, but I kept doing the math
and it kept coming out the same.

Is this where I blame it on the 3rd grade math homework I was doing last
night? I guess I better call my son's teacher and explain... :)

Cool... I'll blame it on the kid.

(man... I can't believe I did that... what a brainfart... It must be that
tumor)

>  As far as I'm concerned, a summing circuit, adds together the voltages at 
>  any point in time.
>
>  Period.

But... And I'm refering to something further down in your message and
something you said earlier... In a mixer, if I split a 1v signal into
channel one and two, then given unity gain through the mixer, what I hear
on the output isn't a 2v signal.

Is 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.

I agree. There will be a mashing of the audio at any point in time where
common frequencies occur in the two audio inputs.

The other side of this is that if I mixed a 400hz sine with an 800hz sine,
I *could* get the original signals back.

Christopher, I guess what I'm tripping over is using "added" and "mixed" as
synonyms. I see adding as a mathematical process (ummm, a proper one), and
mixing as a way to hear two sounds simulaneously, but they aren't
necessarily *directly* interacting with one another. I understand that
acoustically they will interact all over the place, this is the pleasure
(or dread) of sound. But if you shoot one sound out of the left channel and
another out of the right, then the only space that the signals will cross
is in the air. Will the mixed/added sound that your brain percieves be the
same as mathematically adding the two signals and then playing the result
in mono from both channels? Obviously, you'd have to find a way to squelch
your brain of the left/right spacial issues. ie, you wanna be able to hear
in mono.

I dunno... Maybe I just need to accept what you say and not try to fight it.


>  Although, the mixer circuit in the Autoconfabulator mkII did realtime
>  frequency inversion before adding the incoming waveforms - but that was 
>  driven by a microprocessor...

Somehow.. I knew that the Autoconfabulator was gonna show up in this
thread. :)


Sign me... Farted and embarassed,

Mark
---------------------------------------------------------------------------
 Mark Pulver - http://shoga.wwa.com/~mpulver    The "Son of The MIDI Wall"
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