[Harp-L] Re: Harp-L Digest, Vol 85, Issue 56

["Dr. Michael J. Marino, DC" <m.marino@xxxxxxxxxxxxxxxxxxxxx>]

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Sent:Tue, 14 Sep 2010 13:10:24 -0400
Subject:RE: Harmonica Advice

I have to agree with Winslow on this. When dealing with 12 holes you
run into the problem of the upper octave requires much more force to
get response and when you start adding at the other end not only is
there the issues that Winslow so well addressed, but there is also the
issue of swing of the reed to reach the frequency that is desired
without hitting either the comb or the cover. Add to that the need for
a thicker plate as you move down the scale and things get very
interesting.

Working further on reed shape and have found that a base of .25mm can
move anywhere from a half tone to over a 1.5 tone depending on reed
length. This makes for some very interesting research and explains why
when the instruments where first produced that a square shoulder was
preferred. It is much easier to standardize production and tuning
process for a square shoulder reed. The big disadvantage of square
shoulder reeds is that they twist, slightly and at a level that
measuring the twist takes some pretty advanced equipment. The effect
though can be seen in the oscilloscope quiet easily and to a
percentage of people as well. 

Luckily with modern tools (Dental bits like Shofu and such, this does
not remove the flex/twisting though) it is much easier to polish a
reed down and remove part of the problem which is the remaining ridges
left over from manufacturing process.

I prefer a well made 14 hole, as it gives me pretty much the range I
need for most pieces. I tend to fall back on a Tenor when I want to
reach the lower notes. As those usually have the modification to the
comb and cover to allow to movement need by the lower reeds. 

Just my observations and opinions,

Michael