Problems With Duplex Scaling Of Pearl River Grands?

[Geoff Sykes]

Thanks Ron --

Oh, I have no immediate intention of actually going out and trying this. I
just wanted to learn how it was done in case someday I was actually required
to do it.

Oh, I have no immediate intention of actually going out and trying this. I
just wanted to learn how it was done in case someday I was actually required
to do it.

Oops! There I go repeating myself again. :-)

-- Geoff Sykes
-- Los Angeles





-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Sunday, August 19, 2007 8:03 PM
To: Pianotech List
Subject: Re: Problems With Duplex Scaling Of Pearl River Grands?



> At the risk of repeating myself, how does one tune a back, (or a 
> front), duplex? What is the procedure should one of want to try it?
> 
> -- Geoff Sykes

No associated risk whatsoever. You have positively and 
irrevocably repeated yourself. In the negative presence of 
other responses, I'll give it a shot. What the heck, right?

First, most front duplexes are defined by mounds cast into the 
plate, and tuning them will require more guts and a bigger 
hammer than I possess. In the unlikely event that I were to 
attempt tuning the rare movable front duplex, I'd pluck 
segments, and whack the aliquot with a hammer and punch until 
I was satisfied that tuning had been achieved, or was 
convinced that I couldn't do it. Same with the rear duplex. 
Complicating the tuning of rear duplexes is the gang cast 
aliquot bar, with non-adjustable spacing between unisons. When 
the pianos featuring these bars have C-8 measurements ranging 
from 47-mm to 53+, the fixed unison duplex spacing of the 
aliquot bars doesn't fit with much of anything. Again, I'd 
whack the bars around until I was either convinced that I'd 
tuned them, or convinced that I couldn't. Claims ranging from 
enhanced tuning results, to 300%+ increase in sustain times 
have been made in the past for the tuning of gang cast rear 
duplexes. Some doubt lingers. Let us know how it works out for 
you.

Ron N