[sdiy] Phase shifts and instantaneous frequency

[John Mahoney]

-----Original Message-----
>From: Ian Fritz <ijfritz at comcast.net>
>
[snip]
>>it's strange that we were taught that harmonic phases don't matter.  All 
>the old research results have just been thrown away?  Is it because we can 
>only think about linear effects?
>
>Ian 

I assumed that the "phase is indetectable" rule applied only on a waveform-to-waveform basis, meaning that a triangle and an inverted triangle will sound the same.

Once you start dealing with multiple waves summed together, though, it seems obvious to my simple brain that the phase becomes significant.

2 identical sines add up to one sine of double the amplitude, yet
2 identical sines that are 180 degrees out of phase add up to nothing,
and then there are all the in-between cases.

Sorry if I've completely missed the point.

Simply,
John