[sdiy] Harmonic bandwidth

[Tom Wiltshire]

Scott,

On 8 Jan 2008, at 14:11, Scott Gravenhorst wrote:

> I was under the impression that this subject has been proven  
> mathematically, that
> is, that as long as the phase of each harmonic is constant relative  
> to the other
> harmonics that there is no difference in the timbre regardless of  
> the exact phase
> angles.  I'm not really a math heavy, so I don't know if such a  
> proof exists.

I can't see how a purely mathematical proof of whether the human ear  
can hear phase is possible. This is definitely psychoacoustics.

> It seems we're diving into a rather subjective hole again with this.

To be avoided!

> My opinion is that using tools like Cool Edit and Audacity to do
> these experiments is not optimum and could be flawed.

Yeah, this is why I used a simple-as-possible PHP script that I wrote  
ages ago. It just generates harmonic sinewaves

> It's also difficult to
> compare our experiences because of wholly different audio systems  
> as well as
> different hearing abilities.  And I'll throw in the use of MP3  
> compression as a
> further corruption of the data that could add to the confusion.

Yes, again I agree. I used AIFF format because A) it's really simple  
as far as sound formats go and B) there's no compression to help  
confuse things.

T.