Re: [Harp-L] A few thoughts on reeds, since we are muzing it seems.

[joe leone <3n037@xxxxxxxxxxx>]

On Aug 10, 2010, at 9:29 AM, Dr. Michael J. Marino, DC wrote:

>  Since we already know that the frequency you get is a complex result
> (tip width, length of reed, elasticity of the metal, density of the
> metal) why not see if we can take it one set further and see if the
> complex curved free reeds used in concertinas and accordions can be
> applied to the smallest of the family the harmonica.

Some aspects can be used between the two instruments, but keep in  
mind the following:

1... A normal person at rest (sitting watching T.V.) is only taking  
24 ml breaths (abt 1.5 cubic inches)
2... Walking around it's more like 80 ml (5 cu. in.)
3... Deliberate breaths are still only abt 275 ml (17 cu. in.)
4... It takes 500 ml to activate the cyllinder in a breathalyzer or  
the hall of mirrors in an intoxilyzer.
     (a) Most people need 2 breaths (abt  30.5 cu. in.)
5... A small concertina puts out 900-950 ml in normal play (abt. 56  
cu. in.)
6... A Cajun diatonic 1 or 2 row accordion puts out OVER 3 litres.  
( abt 190 cu. in.)
7... Even a small accordion (say 27 keys) can open up to over 10  
litres (abt 625-650 cu. in)
8... there are over 7.5 gallons in a cubic foot. A large accordion  
(say 41 key) can (played by a long armed person) put out well
OVER 9.5 gallons of air.
Pre conclusion? These can rely on Beau-COUP amounts of air.

Conclusion? The reeds in these instruments are geared to this law of  
physics, are usually spring steel (blued) or stainless in the  
slightly better models and bronze in the most expensive models. So  
this has to be taken into consideration.

As for the shapes. That's a different matter and certainly open for  
lots of experimentation. Accordion reeds are usually tapered. THAT is  
an additional expense. They are usually DOUBLE riveted. Another  
expense. The wind savers usually have a thin piece of wire on top of  
them to keep them flat. Another expense. The reeds are usually set in  
pairs on a common plate. There is an air release valve so that the  
reeds aren't over stressed.

Harmonica reeds HAVE to be (relatively) flimsy by comparison.  
Otherwise it would take a wooly mamoth to activate them.

> Bear with me as
> this is not just being a stick in the mud. The complex edge curve you
> find in high quality concertinas and accordion instruments helps to
> eliminate unwanted secondary harmonics that are not naturals of the
> root frequency desired.

This is true.
> Now if this was applied to the harmonica we could get a much truer
> and sweet note from the instrument as much of the noise would be
> eliminated.

Interesting and worth investigating. Accordions stay in tune because  
of their pressure relief valves. Harmonicas go out of tune  
(primarily) because they are played "As a VOICE", and any deviation  
from the normal air flow (bending..over blowing..slurring, etc.)  
risks knocking the reeds out of kilter through stress. Accordions  
cost thousands and thousands and are designed for a certain modicum  
of abuse.
> Now comes the question of how to test and find if this makes a
> favorable sound or one that takes away from the qualities that area a
> harmonica. I am just beginning to look deeply into the math that goes
> with this and it can make you head spin.

Math? well that let's ME out.   :)

smokey-joe & the cafe s


> So anyone interested please
> contact me as the outcome could be very interesting indeed.
>
> Michael