S&S D Duplex -- Long & Meandering

[Richard Brekne]

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Farrell wrote:

> The exchange was: Dan wrote:
> > ....when all other features such as
> > strings, hammers, board, action tuning are correct but
> the duplex is out of
> > tune, by tuning the duplex the sustain increases from
> 100 to 300%. That is a
> > tone that lasts 3 to 4 seconds after tuning the duplex
> scale will last from 6
> > to fifteen seconds. If the tone only lasts 3 to 4
> seconds, what kind of piano is this that all other
> features such as strings, hammers, board, action and
> tuning are correct? Sounds like something is broke to
> me. Terry Farrell What appears inconsistent here follows:
> The subject piano is said to have good strings, good
> hammers, a good soundboard, a good action, and a good
> tuning - and I think it is fair to say that the suggestion
> here is that the piano is a good piano, in good shape, and
> nothing is wrong with it. My comment was meant to suggest
> that if the piano only has 3 to 4 second sustain time,
> that there is in fact something wrong with the piano - in
> fact it may be poorly designed, or lacks appropriate
> downbearing, has a collapsed soundboard - or perhaps it is
> the presence of the rear duplex shiny thingees that is
> choking the sustain?

Hmm... I dont see how these things could be choking
sustain... unless they are simply too close to the bridge
period, and even then I am not convinced its been shown that
too short a back length directly sustain.

Seems that here again we have yet another one of those areas
where when it comes right down to it, there has yet to be
presented any real data to support any of the claims one way
or the other. Lots and lots of "personal experiences".

Ran into an interesting site the other day that might make
this checkable for anyone with a left over piezo tweeter and
a decent FFT program. I will re-read it and post it if it
seems to be what I thought it was.

RicB

--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html


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