Ok, just curious. But you see why I asked.
Jeff
----- Original Message -----
From: Porritt, David
To: caut at ptg.org
Sent: Thursday, February 19, 2009 4:07 PM
Subject: Re: [CAUT] Detuning phenomenon; was: How long to stabilize??
Oh yes, they're both used and used a lot. His students practice in there a lot, and he tries to get them to use the true D though they use the modified one a lot - particularly when he's out of town and won't know.
dp
David M. Porritt, RPT
dporritt at smu.edu
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Jeff Tanner
Sent: Thursday, February 19, 2009 2:47 PM
To: caut at ptg.org
Subject: Re: [CAUT] Detuning phenomenon; was: How long to stabilize??
Not trying to put a wrench in the gears, but is the "unadulterated NY D" played as much as the piano with the laminated bridge caps? Reason I ask is an accidental experiment I did once when an opera coach moved into a vacant piano prof studio for a year with two Bs about 6 or 7 years old, both bought at the same time, both with complete D/C systems, which as best as I could observe, were well tended to. He only used one piano, which I tuned several times during the year and experienced wild pitch changes with every tuning. The piano next to it was rarely used except for events we hosted, but I think tuned 3 or 4 times and experienced next to no pitch change. Amount of use seemed to be what created the difference.
Jeff Tanner
----- Original Message -----
From: Porritt, David
To: Ed Sutton ; caut at ptg.org
Sent: Thursday, February 19, 2009 1:44 PM
Subject: Re: [CAUT] Detuning phenomenon; was: How long to stabilize??
Ed:
We have two Ds here that have the Nossaman laminated bridge caps and they are the two most stable pianos we have. One is in a teacher's studio next to an unadulterated NY D and with humidity changes the stock D will travel further than the modified one. Our other piano with the laminated bridge is in a recital hall along side of a CFIIIS so comparison is not really possible. That room also has better humidity control and also is an internal room with no exposure to the outside.
dp
David M. Porritt, RPT
dporritt at smu.edu
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Ed Sutton
Sent: Thursday, February 19, 2009 12:33 PM
To: Jeff Tanner; College and University Technicians
Subject: Re: [CAUT] Detuning phenomenon; was: How long to stabilize??
Darned if I know!
Lateral is what I'm imagining.
It will depend on the hitch pin location. For the most part the change would probably be the same, front and back, since left sides of the trapezoids will tend to both face the same way relative to the bridge movement. This might account for the strings that are odd men out in the detuning pattern.
Do you think the string slips past the bridge pins on, say, a 6 cents pitch rise? I see this happenning in pianos which were not played during the humidity change, so I don't thing the strings were rendered past the bearing points.
Will it go back in tune if the humidity changes back. I don't know. Perhaps so if we are only talking about, say, a 2 cent pitch change.
I have no idea what kind of lateral pressures would be involved, or if the soundboard wood is capable of generating it.
For an even wilder thought, consider that if the bridge shrinks or expands enough, the angles of the bridge pins will change!
Probably more productive to think about changes in bridge cap thickness. Ron Nossaman may be able to send some statistics about his laminated bridge caps. He also lives in pitch adjustment hell, so may have more experience to share.
Ed
----- Original Message -----
From: Jeff Tanner
To: Ed Sutton ; caut at ptg.org
Sent: Thursday, February 19, 2009 1:02 PM
Subject: Re: [CAUT] Detuning phenomenon; was: How long to stabilize??
You're referring to the shape created between the capo and the speaking length bridge pins, and you are speaking of a lateral shift rather than vertical, correct? If that was all that was involved, your theory makes sense. But from the non speaking length pins to the hitch pins, wouldn't the reverse be created, somewhat cancelling it out? The overall tension will eventually equal back out after a shift, right? How would such changes in tension not also somehow affect the center string, it being also either shared by the left or right unison?
Just thinking with you.
Tanner
----- Original Message -----
From: Ed Sutton
To: caut at ptg.org
Sent: Thursday, February 19, 2009 12:40 PM
Subject: Re: [CAUT] Detuning phenomenon; was: How long to stabilize??
Would a small shift of the bridge to one side effect the left string more than the right, since the strings are not perpendicular to the line of the bridge pins? The outer strings create a long trapezoid, thus a shift of position would increase the tension on one and decrease it on the other.
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