[CAUT] pre-stretching new string?

[Bob Hohf]

> -----Original Message-----
> From: Ron Nossaman [mailto:rnossaman at cox.net]
> Sent: Saturday, June 09, 2007 9:19 PM
> To: rhohf at centurytel.net; College and University Technicians
> Subject: Re: [CAUT] pre-stretching new string?
> 
> 
> > I've been following this discussion with some interest, and don't have
> any
> > strong opinions or data on one side or the other of the
> soundboard/bridge
> > debate.  However, I'd be interested in how the various factions explain
> the
> > difference in humidity-related pitch change between the treble and bass
> > bridges.  We've all observed the same sort of difference with both
> > solid-body and cantilevered bridges, so I don't think it can be
> explained by
> > simply saying, "Bass bridges have more wood, so they expand and contract
> > more."
> 
> Hi Bob,
> Tell me, how would having more wood and expanding and
> contracting more have any reasonable hope of producing better
> tuning stability? This stuff works by real rules in the real
> world, so the conceptual model has to make rational sense
> somewhere.
> 
> 
> >And how about those Yamaha C3s where the lowest octave of the tenor
> > bridge has far greater seasonal pitch swings than any other part of the
> > scale, treble or bass?
> >
> > Just wondering
> >
> > Bob Hohf
> 
> Once again. Strings at a tension putting them at a lower
> percentage of breaking tension change pitch more for a given
> length change than strings at a higher break%. The low tenor
> in way too many scales is too low a break% because the less
> than stellar scaling approach has the speaking lengths
> foreshortened because the bass/tenor break is too low in the
> scale to allow adequate speaking length in the lowest tenor
> note and still fit in the piano. That's it. In most scales,
> the bass is at a higher break% than the low tenor, often
> *much* higher, so the mechanism that changes string lengths
> with humidity changes produces the greatest pitch change in
> the low tenor - which is typically at a lower break% than
> everything around it. Using Sanderson's scaling formulae
> against what we observe in the physical world, it becomes more
> obvious all the time that there are real cause and effect
> relationships at work here.
> Ron N

Hi Ron,

Thanks for your comments, but I'm afraid that I'm one of those who's doomed
to an eternity of skepticism regardless of how many times you repeat it.
Based on the discussion and my own experience, the only thing I would say
with certainty is that the causes behind the effects are debatable.  But
isn't this the name of the game when it comes to pianos?  It's relatively
easy to make all kinds of observations of what is happening, but then coming
up with the definitive "why" is often very difficult if not impossible.

> I dont try at this point to explain this or related questions.  

I appreciate this comment from Ric.  It doesn't bother me a fig to admit
that I just don't know why.  My experience also suggests that having
plausible explanations usually has little or no influence on what I do in
the shop.  I've done plenty of research and analysis over the years, which
has been useful in understanding what the options are.  But in the end, I
usually toss it all and do what seems best. 

I think we should avoid going the way of today's climate scientists.  They
have unbelievable tools to play with, and can generate and crunch huge
mounds of data.  The problem I have with them is that they expect us to
believe they know how to predict the climate when they can't even forecast
the weather.

Bob Hohf