Duplex

[David Ilvedson]

I would think that Reyburns Cybertuner could show the before and after
effects of tuning the duplex on a note?

David I.

*********** REPLY SEPARATOR  ***********

On 10/26/01 at 9:36 AM Delwin D Fandrich wrote:

>----- Original Message -----
>From: <Duplexdan@AOL.COM>
>To: <pianotech@ptg.org>
>Sent: October 25, 2001 11:14 PM
>Subject: Re: Duplex
>
>
>> Dear Dave,
>>
>> Does the Baldwin have a Duplex Scale?
>
>As currently designed and built, all grand pianos have what can be called
a
>duplex scale. The phrase comes from the Latin 'duplex,' literally
>"twofold,"
>from plicare "to fold." The question is, is the length of the duplex
>specifically and intentionally tuned to some partial of the fundamental
>string length?
>
>
>
>> Old Baldwins were made with triangular shaped oliquots, before the
>acu-just
>> system went into effect. All of these vintage pianos with adjustable
>oliquots
>> were designed to have a specific duplex scale tone that coordinated with
>the
>> tone of the speaking length. The moveablility of these oliquots was
>> incorporated to allow for this tuning process.
>
>Earlier Baldwin's had the back string rests pinned to a hole drilled in
the
>plate. They are not movable. The change was made as much for cost-cutting
>reasons as to allow for 'tuning' them. There is no evidence that tuning
the
>back scale with these string rests improved the performance of the piano,
>hence the subsequent change to the fixed vertical hitches.
>
>
>
>> Tuning the duplex scale of any and all of these pianos can
unquestionably
>> improve the tone of the piano in particular regard to the quality of
tone
>and
>> the sustain.
>
>Oh, I think there is considerable question about this. My own actual
>measurements revealed a slight increase in power at the affected
>frequencies
>during the initial attack period and immediately following but this was
>followed by a decrease in sustain as the energy coupled to the tuned
>duplex--the aliquot part--was (presumably) absorbed into the plate.
>Experientially, the tuned duplex system has also proven to be the cause of
>much unwanted string noise.
>
>It seems to boil down to a choice: with the tuned duplex system you might
>get a slight increase in initial attack volume at certain harmonics. In
>exchange you will have slightly shorter sustain and the increased
>probability of string noises. Or, you can design the soundboard such that
>sustain time is not--and does not quickly become--a serious problem and
>forget about the tuned duplex system and its attendent string noise
>problems. Personally, I prefer the latter approach.
>
>
>
>> May I remind you that this is not my idea; it is, was and always will be
>CF T
>> Steinway's, who has the original patent, 126848.
>
>What can I say? Lots and lots has been learned about the piano and its
>design since old CFT sat in front of a drafting table. Smart as he was, he
>wasn't perfect. Nor was the piano he created (in spite of the claim of
>certain of his descendents). It was--or should have been--just one
stepping
>stone on the path, albeit a significant one. If our industry is to
survive,
>however, we must learn from both his experience and our own and then go on
>from there.
>
>Del