[sdiy] Basic waveform question

[Tom Wiltshire]

David,

There's been plenty of discussion on this list before about the  
weaknesses of the "standard" theory around this area, but the  
schoolbook answer is something like this;

The ear doesn't hear phase, so a ramp at -1 amplitude and a ramp at  
+1 amplitude are the same.
If you add that ramp to another waveform, you will likely either  
reinforce certain harmonics or cancel them. This should produce  
audible differences.
Adding the sinewave to the -ve ramp or square ought to remove the  
fundamental from the waveform. The triangle will do much the same,  
except it will also have a limited effect on the 3rd, 5th, 7th, etc  
harmonics too. I'd have expected to be able to hear this, but after a  
while it might just sound like a load of buzzy synth-type waveforms.  
At this point you need to go and sit on a quiet riverbank for a  
little while!

T.



On 4 Feb 2009, at 09:19, David G. Dixon wrote:

> I've tacked a little wave morphing circuit onto a VCO which can
> independently adjust the of ramp and square waves from -1 to +1 and  
> add
> either or both to varying amounts of sine or triangle waves.  The  
> resulting
> waveforms look very different on the scope when positive or  
> negative amounts
> of ramp or square are added, but I'm not sure that they sound  
> different.
> Are they supposed to?
>
> David G. Dixon
> Professor
> Department of Materials Engineering
> University of British Columbia
> 309-6350 Stores Road
> Vancouver, B.C. V6T 1Z4
> Canada
>
> Tel 1-604-822-3679
> Fax 1-604-822-3619
>
> "PERFECTA FINGAMUS SERVIAT NATURA"
>
> The information in this email and in any attachments is  
> confidential and
> intended solely for the attention and use of the named addressee 
> (s).  It
> must not be disclosed to any person without the writer's  
> authority.  If you
> are not the intended recipient, or a person responsible for  
> delivering it to
> the intended recipient, you are not authorized to and must not  
> disclose,
> copy, distribute, or retain this message or any part of it.
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>