Thanks Brendan for your thoughtful contribution to this discussion. This still seems to me to raise the question, what exactly is it that the player is perceiving as different? Suave Blues Man's suggestion to test this objectively seems to me the only way to go from here.
During my comparison of around two dozen otherwise identical combs with specific differences in material and finish, using identical covers and the same two sets of reed plates, my notes showed consistent differences in sound. I have no doubt that these differences actually exist, and even though they are relatively small and may not be noticeable to the listener, I notice them. I assume they are the result of slightly different acoustic overtone profiles, which will be measurable in the same way as for example the sound of stainless steel reeds is verifiably different from the sound of brass reeds, even though most listeners won't notice the difference. How or whether the difference is perceived and interpreted (or not) by the listener doesn't necessarily have any bearing on whether or not it actually exists.
In Vol 61/83 Ken (Mojo Red) mentioned our comparison at SPAH between his MB Deluxe fitted with the brass comb and my standard MBDL. Not surprisingly, his one was noticeably louder than the harp with the wooden comb, which is after all one of the reasons why people spend a load of money on metal combs.
I presume the difference is caused by the fact that the acoustic conductivity of brass is higher than that of wood and the inner surfaces reflect sound waves more strongly, both of which contribute to making the instrument sound louder and brighter.
In order to document the effect of comb material on sound it should only be necessary to play the same sustained single notes with the same air pressure and size of air column on all test combs (using the same reed plates in each case) while recording the overtone profile and the volume. The harmonica can easily be blown/drawn mechanically, which ought to satisfy even the most hardened sceptics. I have arranged to run tests later this year in the Hohner acoustics lab to objectively measure any differences and will post the results here, so maybe we can then finally lay this subject to rest,
Vern Visit my harmonica website www.Hands-Free-Chromatic.7p.com
Steve
Steve Baker steve@xxxxxxxxxxxxx www.stevebaker.de www.bluesculture.com www.youtube.com/stevebakerbluesharp
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