Soundboard Thoughts

Danny Moore danmoore@ih2000.net
Wed, 10 Dec 1997 10:42:29 -0600


Horace Greeley wrote:

> I'm not sure about 6 or 7 seconds, maybe Del could shed some light, but
> certainly some
> improvement might be possible.

This demonstration was on a 30 year old console that had some real unpleasant
screeching overtones about the 7th and 8th partials.  My guess was that there
were some inherant impedance problems that allowed those partials to continue
to sing as the lower partials decayed too quickly.  I suspect that the lead
weights damped the objectionable partials while allowing the lower partials to
resonate more naturally.  I guess there could have been some comb filtering
within the board that caused the more desirable partials to be cancelled.

Again, this was mere speculation - I'm not a physicist.

Danny

>
>
> Horace
>
> At 11:52 PM 12/8/97 -0600, you wrote:
> >Susan,
> >
> >Wouldn't this sort of work as the inverse of weighting soundboards?  I've
> never
> >heard a plausable explanation of why the lead weights work, but I've heard
> 1 or 2
> >well placed weights add 6 or 7 seconds to bass sustain while damping out
> >unpleasant overtones..
> >
> >Danny Moore
> >Houston Chapter
> >
> >Susan Kline wrote:
> >
> >>  use a router and/or plane to thin one side, with the strings still on
> >> and at pitch. Possibly they could add mass to the other side as well, by
> >> gluing or clamping something to those ribs..
> >
> >
> >
> Horace Greeley
>
> Systems Analyst/Engineer
> Controller's Office
> Stanford University
>
> email: hgreeley@leland.stanford.edu
> voice mail: 650.725.9062
> fax: 650.725.8014





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