Duplicity on a Grand Scale

[Ron Nossaman]

>Ron,
>    That is pretty interesting. I wonder if various confugurations of
>duplex (i.e angle and length) result also in a change in timber of the
>tone which bleeds across.  Perhaps an adjustable couterbearing bar could
>be built for a few notes on a real piano.  Then test with the RCT
>pianalyzer how various configurations of duplex affect relative overtone
>intensity.  Perhaps one could control/voice or bleed out from the
>speaking length the undesireable overtones into the duplex, i.e a useful
>duplex.
>Just a thought.
>-Mike
>
  

Hi Mike,
The angle and length sure affect volume and pitch of the duplex. It would be
easy enough to set this up and test it, if you had access to RCT, but I
doubt that it would ultimately be of any use. From what I've seen, heard,
and done, I've got to go with what Del's been saying about front duplexes.
If the soundboard works, you don't need them, and they don't really work as
they were intended to in the first place, so there's no point to them in any
case. What they steal in string energy doesn't seem to me to be worth the
nasty noises they make. High bearing angle for better termination, and short
lengths to keep them out of the tonal result, and you never have to "dink"
with them again. Like I tried to point out in an earlier post. If they are
an enhancement, rather than a patch, why aren't they designed into the
entire scale? Why only the low end of the killer octave on up? They are an
attempted fix for a soundboard design problem (that doesn't work) and most
everyone is looking at it from the wrong direction entirely. Anyway, I was
intrigued that there was so much bleed through in all areas of the scale,
and at any bearing angle that I came across. This also makes me wonder how
much power the understring felt in the agraffe section is stealing from the
speaking length. Again, like Del has been saying, that half oval brass bar
would be a better choice. 

Just trying to throw a small brick or two into the prevailing attitudes
about this stuff. Since the accepted gospel concerning front duplexes
doesn't work the same way twice in a row, there could, perhaps, be a minor
flaw in the accepted reasoning. You think?

Ever a Lert, 
 Ron