Re: [Harp-L] comb material

["Rick Dempster" <rick.dempster@xxxxxxxxxxx>]

For years I searched for a way to amplify the harmonica without using
electronics. I thought that the harmonica reed worked like the tines on
a music box, and therefore could be amplified by connecting the riveted
end of the reed to a resonating surface. If you have ever tried holding
a music box mechanism in your hand as it plays, and strained to hear
it's barely audible tinkle, and then, placing it on a table, been amazed
at the sudden increase in volume, you will see how my mind was working.
The same thing applies with a tuning fork. At one stage I envisaged an
appuratus like the head of a clockwork gramaphone (and thus like a
resonator guitar) somehow adapted to the harmonica.
But this is not how the harmonica works. There is virtually no
vibration at the reed end. All the sound is produced, as Vern has said
again and again over the years on this list, by the 'siren' action of
the reed in the air.
If you pluck a reed with your finger nail, you will hear the note. If
you hold the reed plate against a heavy peiece of resonant timber (door,
table, piano etc.) and repeat the action, you will observe NO INCREASE
IN VOLUME.
As far as I am concerned, the case is closed.
(Oh, by the way, the only way you can 'amplify'  the harp without
electronics is with a megaphone, like Deford Bailey.)
>>> "Vern Smith" <jevern@xxxxxxx> 18/04/2007 6:36:04 >>>

----- Original Message ----- 
From: "Garry Hodgson" <garry@xxxxxxxxxxxx>
To: <harp-l@xxxxxxxxxx>
Sent: Tuesday, April 17, 2007 10:36 AM
Subject: Re: [Harp-L] comb material


> Zombor Kovacs <zrkovacs@xxxxxxxxx> wrote:
>
>> My metal combed harps do sound significantly different
>> from the plastic ones.
>
> unless they're identical in all respects but comb material, and
> you and your audience don't know what you're playing, it doesn't
> tell us much.  there is a well established methodology for
discerning
> differences like this in controlled and repeatable experiments.
> to my knowledge, this has not been done with harps.

It has been done twice.  Once at SPAH 97  and again at Buckeye 98. 
Complaints arose that the comparisons were "flawed"....AFTER the
results 
disappointed the believers.  There should be a lot of discussion in the

harp-l archives circa '97 & '98.  Comb materials as diverse as lead,
foam 
plastic, wood, titanium, ABS plastic, balsa wood, aluminum and concrete
were 
compared.  None of the more than 30 SPAH attendees present did better
than 
random guessing.  At Buckeye, the same set of reedplates and covers
were 
used with wood and plastic comb materials.

Neither the above empirical evidence nor musical-acoustical theory
supports 
the notion that comb material perceptibly affects tone.  That is
because the 
comb does not participate in the generation or the transmission of the

sound.  The notion arises in a false analogy with the materials of
sound 
plates in stringed instruments. It is well documented in
musical-acoustic 
books (references on request) that the materials of wind instruments 
including woodwinds, brass, and organs, do not perceptibly affect tone.

There are comparisons of concrete flutes, plastic-tubing one-note
clarinets, 
and putty-covered trumpets to deny the effect.

It would only take one person winning my $1000 challenge to prove that
it 
could be done and elicit from me a public admission that I have been
wrong 
for ten years. The comb materials effect is a cherished myth and
refuses to 
die quietly. It is like killing a snake...just when I think that I have

beaten it to death, it starts wiggling again!   ;o)

  > http://en.wikipedia.org/wiki/Double_blind 

Vern
Visit my harmonica website www.Hands-Free-Chromatic.7p.com 



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