Re: [Harp-L] Comb Design

[Vern <jevern@xxxxxxx>]

The design of the weight assembly anticipated your objection.

No "mass was added to the combs."   An external weight was attached to the harmonica so that brass combs could not be detected by the overall heft of the instrument. The weight assembly was held by the cover screws and did not even touch the comb. The acoustical properties of the comb, if any, were not affected.

The brackets that attached the weight were much more flexible and could constrain any possible comb vibration very much less that the reedplates and covers. The reedplates, in particular, are much stiffer and are screwed to the comb.  The constraint and damping of the reedplates and covers make it unlikely that the comb of a harp can vibrate in any significant way.  

Vern

On May 22, 2011, at 8:50 AM, Derwood wrote:

> Vern,
> 
> I make no argument that the sound projected to the audience is effected in any discernible way by the material of the comb. What I notice is that I like my harmonicas with solid combs better. It is hard to tell if it is the noticeable weight difference (it feels more sturdy, better) or the effect on the mass of the harmonica that is in the transmission path of the sound waves through my body. 
> 
> A question about the SPAH2010 experiment: Was this the one where mass was added to the combs so that the player could not distinguish the material by weight of the harmonica? If so then it would not be a good experiment to show the invalidity of my theory on the sound transmission through the body. 
> 
> Derwood
>