Tuning the Duplex (was ...Capo)

[Delwin D Fandrich]

I think, Don, you're talking about the front duplex and Dan is talking about
the rear duplex. (But I could be wrong.) Much, if not most, of the energy
that bleeds past the V-bar in a tuned front duplex (or aliquot) system is
absorbed into the plate. It's not just stored there waiting to be sent back
to the vibrating string, it's dissipating into that energy-absorbing gray
iron plate that we are so proud of.

And I'd sure like to see that 300% increase in sustain time verified. Dan,
do you really mean that if I have a unison with a useable 15 second sustain
time that you can improve this to 60 seconds just by tuning the rear duplex?
Pardon my skepticism, but...

Del


----- Original Message -----
From: "Don" <pianotuna@accesscomm.ca>
To: <pianotech@ptg.org>
Sent: September 05, 2002 1:19 PM
Subject: Re: Tuning the Duplex (was ...Capo)


> Hi Dan,
>
> Exactly what I suggested. Energy is stored in the duplex and then
> released...increasing sustain. It can only act as buffer/filter/storage
for
> energy--it is not struck so it can not create *more* energy--it can only
> absorb. Thanks for doing the research to prove it.
>
> Now if a person used a real time sound analyser......
>
> At 01:47 PM 9/5/02 EDT, you wrote:
> >Duplex Effect,
> >
> >the comment that the duplex "absorbs, bleeds and filters" energy is
> >interesting. Is there any scientific data or have any experiments been
done
> >to pursue this line of thinking. If so, I'm sure they would be welcome
> >additions to the litrugy on the subject.
> >
> >However in the dearth of scientific experiments proving the duplex is a
> >misfunction I would like to point out that a major plus function in terms
of
> >energy is the duplex's capacity to increase sustain by more than 300%.
This
> >was recently proved in Penna and in Vermont in two of my seminars where i
> was
> >fortunate to do a duplex tuning procedure on two instruments whose
condition
> >was rebuilt A ! in tone, workmanship and materials. All I did to these
> >instruments was tune the duplex according the principles established by
the
> >inventor and the sustain was remarkably increased.
> >
> >This is the only energy guide that I have at my disposal. Are there
others?
> >
> >Dan Franklin
> >
> >
>
> Regards,
> Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.
>
> mailto:pianotuna@accesscomm.ca
>
> http://us.geocities.com/drpt1948/
>
> 3004 Grant Rd.
> REGINA, SK
> S4S 5G7
> 306-352-3620 or 1-888-29t-uner