Problems With Duplex Scaling Of Pearl River Grands?

[Richard Brekne]

Hi Geoff

Not exactly, but within the parameters of what the actual string segment 
length allows for, yes. Thats what I'd call <<tuning>> the back duplex.  
Determining and setting this segment length is the other half of the 
whole thing.  Goes without saying really. That is done by adjusting the 
position of the bars just forward of the hitch pins.

A little study into what the back duplex is "meant" to do, and a little 
experimentation with both adjusting the string segment lengths and, once 
thats done, tuning the string segment as per your answer below can be 
quite interesting.  Its not particularly time consuming either.

The front duplex in principal is the same thing.  Its just harder to 
adjust the length because it involves as a rule grinding down the plate 
and installing some sort of counterbearing bar.  Older Steinways had an 
adjustable system here.... wish they still had really.  But thats 
another issue.

Cheers
RicB


    So setting the back duplex is more or less a process of massaging that
    so-called non-speaking length of the string until you like where it is,
    correct? With the amount of friction across the bridge pins I understand
    that once it is set it's pretty much going to stay there.
     
    Since the front duplex does change whenever you tune the piano, are we
    pretty much stuck with wherever it decides it's going to be once we have
    stabilized the string with some firm key whacks? I frequently find these
    much more objectionable, than the rear ones. And louder, too.
     
    -- Geoff Sykes
    -- Los Angeles