Re: [Harp-L] comb design/structure

["rick epping" <rickepping@xxxxxxxxx>]

In 1994, when adapting the design of Special 20 comb for Hohner's Chinese
Richter models like the Pocket Pal and Bluesband, I conducted tests on
Special 20 combs, comparing their performance with and without the
reinforcing bars.  I thought I found a very slight difference between them,
with the reeds in the lower cells having a slightly better tone without the
bars and those in the higher cells having a slightly better response with
the bars. I believe the high reeds benefit from the presence of the
bars because the bars raise the resonant frequency of the cells, bringing
them closer to the reeds'  natural frequencies.  So when setting up a
Special 20 I will often remove the bars from cells 1-6 and leave those in
cells 7-10.  For the design of the injection mold for the Chinese models I
gave the connecting bars a more aerodynamic, lanceolate profile, which I
found to also slightly improve performance.

The amount of difference between the designs - bars or no bars, rectangular-
or lanceolate-profiled, I found to be slight, bordering on imperceptible.
But it's the sum of all the little things that can add up to a good harp.
As my father used to say to me when I was a kid, sweeping up the sawdust in
his cabinet shop on Saturdays, "Take care of the corners and the middle will
take care of itself."

Best regards,
Rick