Compression waves

[John Delacour]

At 11:20 AM -0600 11/20/01, Ron Nossaman wrote:

>You might also bear in mind that his statement about the longitudinal mode
>frequencies being at least ten times that of the fundamental transverse
>frequency relates to plain wire strings, as does his rough formula of
>2500/L that I posted earlier. He says that wrapping the core lowers the LM1
>(longitudinal mode fundamental) significantly and reasonably predictably.

I've read only the lecture abstract at kth.se and there this is not 
said.  From this you would get a different impression.

>That whistle in the LM of the core you tested was it, and that is the
>significant frequency relationship for everything that isn't wrapped. That
>would be essentially every string with supposed tuned front and rear
>duplexes, unless you have seen these features connected to wrapped strings.

That makes sense, but everything I have read there is in the context 
of covered strings and all the demos are with transverse frequencies 
lower than 50 c/s.  I've had no luck getting IE to display the tif of 
the patent either on the Mac or on WinNT, though both machines have 
all that's needed.  I'll have one final go with another version of IE 
on the Mac and if I get no joy, perhaps I can impose on you to zip 
the images and send them to me.

>Meanwhile, go to http://www.uspto.gov/patft/ and look up patent# 3,523,480.
>Print it out and find your magnifying glass. Also try to get a copy of
>"Design and tone in the mechanistic piano. Part III. Piano strings and
>scale design" as was published in the Journal of the Acoustical Society of
>America in 1996.

I had better luck with a 1999 patent from Frank Ellis p/n 5,874,685, 
which is most interesting since not only does it continue from 
Conklin's prior art but approaches the problem from another angle. 
This patent disclosure does answer some of the tentative questions I 
listed and provides a lot of useful insights, though not all his 
premises are 100% correct.  The material is well-presented and I 
thoroughly recommend it.  Ellis is most concerned with the nasty 
sounds in the tenor area, which we are all so familiar with and in 
explaining the origin of these and how to eliminate them, he clears 
up the question of the interaction of the transverse mode and the 
longitudinal mode, which is at the heart of the matter.  He also 
shows that my question as to combination tones was not irrelevant 
either.

Anyone know who Frank Ellis is?

JD