Re: [Harp-L] Virtual Hole Technique gets Scientific!!!

["Jim Greenwald" <staggerin@xxxxxxxxx>]

Hi

Winslow says:
> If the second partial were as strong as the first, you'd definitely hear 
> an octave. <

I don't think this is the case. What makes us hear an octave is the 
coincidence of two STACKS of partials (either 'complete' or at least 
containing the significant partials) one of which is an 100% multiple of the 
other.
In the harmonicas I've looked at, the second partial is characteristically 
very nearly as strong as the fundamental.  Averaging about + or- 1 dB from 
fundamentals that are already -27dB. When these two frequencies are added, 
you hear a single tone that's nearly 3dB louder than either alone - but not 
an octave.
The strongest single component of the harmonica 'stack' is the third partial 
(the fifth above the fundamental) which averages over four times the 
'perceived loudness' of the fundamental. That doesn't make us hear a power 
chord. See what I mean?

I think this is just a matter of an apples and oranges use of the term 
'octave'. Winslow has forgotten more about music than I'll ever know 8^)

I did a little experimenting, and it sounds like if the fundamental on this 
particular harmonica note can somehow be reduced about 15-18 dB then the 
tone will may be perceived to be an octave higher. The fundamental doesn't 
even have to be reduced that much if the second partial is also reinforced. 
On a Seydel 1847 I just measured, the fourth partial (also a major seventh - 
F#7) is very strong as well, at less that 1dB down from the fundamental. 
That being said, I haven't a clue how this reduction of the fundamental is 
accomplished in real time. You can only do so much by changing resonance.

In Joel's videos - so far I don't hear it. The momentary substitution of the 
lower major seventh (7-hole draw) out a split embouchure is not a new 
technique however - in diatonic accordian or harmonica. Still, it doesn't 
make the illusion any less fascinating.

Cheers,
Staggerin' Jim
Listen to Roots Harmonica at http://www.live365.com/stations/staggerinjim


----- Original Message ----- 
From: "Winslow Yerxa" <winslowyerxa@xxxxxxxxx>
To: <harp-l@xxxxxxxxxx>; "Joel Thomas" <theloveboxquartet@xxxxxxxxxxxxxx>
Sent: Friday, June 27, 2008 4:54 PM
Subject: Re: [Harp-L] Virtual Hole Technique gets Scientific!!!


> If the second partial were as strong as the first, you'd definitely hear 
> an octave.
>
> But under what special circumstances would you get such an abnormally 
> strong second partial? Usually when you play the harmonica, you don't hear 
> it as producing two notes an octave apart. Fooling the ear with 
> surrounding circumstances (the surrounding notes are played as octaves, so 
> this non-octave note is heard as an octave as well) is one thing. Getting 
> a measurable result is quite another, so the question to investigate is, 
> how come? (Could your test equipment be delivering a false or distorted 
> result?)