[pianotech] BB Mason and Tenor Cross over

[David Love]

Right but with increased tension also comes an increase in the Z factor
which also contributes to the tonal change which is, perhaps, a reason that
simply matching tension doesn't really work in that area.  You just get a
loud honk.  I'm just wondering, do you actually hear BP% differences (I'm
not convinced that you do) or, in this case, is the change in tensile
strength manifested in some other factor that would balance out the tension
difference?

David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Sunday, December 20, 2009 8:55 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] BB Mason and Tenor Cross over

David Love wrote:
> Which begs the question, does the tone come from the relative BP% or the 
> relative tension.  Seems that even if you use a wire that has a  higher 
> BP% the tension is still too low to match the other notes in that 
> section.  On the B you go from about 160lbs to about 120 lbs at the break.


Tension's easy, increase wire size. With low tensile strength 
re-bar you likely just trade one tonal problem for another, 
but hey, you might dislike the new problem less.

The fact is that these pianos are just really bad scale 
designs, and aren't going to be "fixed" without moving 
bridges. Even then, doing it right would take you back to the 
drawing board.

Ron N