Re: [Harp-L] SPAH 2010 Comb Test: a thought experiment (long)

[Michelle LeFree <mlefree@xxxxxxxxxxxxxxxxxxxxxx>]

 Rick Dempster writes:
> I admire Vern's patience over all these years.

Me, too! There's lots to admire about Vern.

> I always say to myself that I won't chime in on this again, because I'll just be repeating what's already in the archives.

Me, too. But I think this is a novel way to analyze what's going on 
inside a harmonica that you won't find in the archives.

> What the hell! Here goes one of my favourite examples again:
> Observing that the inside of a music box looked a little like a set of harmonica reeds, I always believed that it might be possible to amplify (non electronically) the sound of the harp.

There ~is~ a way to non electronically amplify the sound of a harp. 
Douglas Tate called it, "playing loudly, softly." He pointed out that a 
player can use his/her hands to form an Helmholtz resonator:

http://physics.kenyon.edu/EarlyApparatus/Rudolf_Koenig_Apparatus/Helmholtz_Resonator/Helmholtz_Resonator.html

Douglas described in his book, "Playing the Harmonica Well," how he was 
able to be routinely heard well playing un-amplified with an orchestra. 
Robert Bonfiglio does the same thing all the time. Douglas described how 
a player can learn to tune the size of his hand cup to the frequencies 
of individual reeds to greatly amplify the resulting sounds (smaller cup 
for high notes; larger cup for low ones).

(Sorry, a bit oblique to your post, but relevant none-the-less, methinks.)

> Holding the mechanism of a music box in your hand, the volume is tiny. Place it on a solid wooden table, and, like a tuning fork, the volume is magnified many times and is perfectly audible.

Yes, the table surface is vibrating much like the top of an acoustic guitar.

> Now get someone else to blow a harp held in their hands as usual, then have them place the back of the comb against the same solid wooden mass that so amplified the music box mechanism.
> The difference? Nil, because of the lack of vibration transmitted from the reed to the comb.
> (BTW the reason I say 'someone else' is so you can hear properly. If you squish yourself up against the table or whatever, the closeness to the sound reflections might cause you to think there is an increase in volume. From a few steps back, there is clearly none.)

I respectfully disagree here, Rick. I won't debunk your experiment, 
though I think it is severely flawed. I will stop at simply pointing out 
the irrefutable fact that players can feel their harmonicas vibrate in 
their hands and mouth. That fact alone is enough to disprove your 
assertion about the lack of vibration transmitted from the reed to the 
comb and therefore negate the results of your experiment.

> With the music box reed, the tuning fork and the guitar string, you are hearing the bell-like resonance of the metal. With the harmonica/accordion reed, you are hearing the whirring noise of air being chopped up, like the sound of a fan or an aeroplane propellor (do the materials of a plastic/metal/wood  propellor/fan cause respective differences in sound? I think not.)

Geez, Rick, that's a faaar bigger leap than ~I~ can make here.

> I wish to hell the pro-materials-makes-a-difference mob were right; I would love my harps to be as loud as a trumpet or sax with no electronics involved. I have mucked about with trying to attach a reed to a guitar-face and to an old clockwork gramaphone head (read 'resonator') but it don't work.
> Does anybody not wonder why the Dopyera Brothers or some other mob back in the 20s didn't try to amplify the harp with a resonator, like they did the guitar, mandolin, violin, ukulele and gawd knows what else? If there'd been a buck in it, they would've. They didn't, because you can't. Go on! have a go!
> The whole thing is a no-brainer.
> Your's empirically,
> RD

Rick, I don't recall anyone ever talking abut amplifying the harmonica 
in this thread. I was merely pointing out that there is meaning in the 
fact that harmonicas vibrate in a player's hands and mouth re: the comb 
experiment. I respect the fact that you seem to disagree, but I'm afraid 
your experiments and arguments don't hold water even for a casual observer.

Sorry,

Michelle