[pianotech] Soundboard problem?

[Roger@Integra.net]

Claude,

Your clinical analysts of the soundboard suggest you may be relying too much on correcting downbearing to exact your expectations. Certainly downbearing is an important ingredient, but ignoring other soundboard principles may point to a limited and possibly disappointing outcome. Your letter makes little mention of the overall tonal characteristics of the soundboard. Experienced technicians will listen to the overall quality of tone to indicate if there is a potential problem with crown and other factors.

One of the principle ingredients of the piano sound is created by the tension between the ribs and the soundboard panels – which manifests itself through crown. Your description suggests this may be lacking. If so, all the kings horses and all the kings men will not restore this piano to the potential, commensurate to the money your customer will be paying for restoration.

Use extreme caution, lest you damage your reputation.

Roger Gable

P.S. Your suggestion to add material to the bridge to correct downbearing will likely gain you nothing but increased downbearing without any (or possibly negative) tonal benefits.



Sent: Thursday, December 29, 2011 6:06 PM
To: pianotech at ptg.org 
Subject: [pianotech] Soundboard problem?

 

 

  I have a 1925 Lyon & Healy (5 ft.) grand in the shop.  I have done a preliminary estimate on restringing, new hammers, action reconditioning, etc., but I do not yet have a signed contract with the specifics spelled out.

  I have been doing some closer inspection of the piano, have concerns about the 

soundboard, and could use some counsel.  

  The strings are still on, and composite downbearing readings (Fowler guage) from the top note run 

.004" - .010" in Treble 2;

.006" - .009" in Treble 1; 

.010" - .009" in Tenor.

  These seem minimal, especially in the top treble, and I will check again after taking off the strings to see how much the board might come up, but maybe I can work with these, especially since I may have to recap the top end of the treble bridge anyway.

 

  The bass is the main problem.

Top note (28) reads .010".  (That's okay.)

Middle of bridge is .006", and it ranges .004" - .007" through note 4.

THEN, #3 is .000", #2 is -.001", and #1 is -.003".

 

Inspecting board underneath shows all glue joints solid and at least minimal crown except for the low end of the bass bridge.   A straight edge will rock at that point directly beside the lowest soundboard button for the bass bridge apron, although there is clearance and "crown" on either side of that spot.

   Tone in bass is not strong; bass bridge is offset construction; clearance between plate and soundboard at plate screw/post locations is minimal (1/8").

Perhaps I could re-cap the bass bridge to correct downbearing.  Could I save this board, and should I even try.  My preliminary estimate did not mention replacing the soundboard and was based on a home inspection in a crowded room where getting under the piano was difficult (That's my best excuse. J)

  Counsel welcomed.  Criticism accepted.

Thanks.

Claude Harding

 

 
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