[pianotech] Bass String Length Mismatch Tuning Trouble

John Delacour JD at Pianomaker.co.uk
Fri Jan 7 05:51:10 MST 2011


At 06:49 -0500 07/01/2011, Terry Farrell wrote:


>I don't have much experience with un-equal length bass string 
>unisons that can't be tuned beatless being fixed with new 
>equal-length strings. Has anyone done this, and can anyone offer an 
>experienced opinion on whether lengths of a couple millimeters 
>difference in the wrapped speaking length in a pair of unisons would 
>commonly present tuning problems?

If it did then most Steinway grands would do so.

>Needless to say (I think?), I found all the bicord pairs in the 
>picture below to be impossible to tune beatless - the best I could 
>do was leave most of 'em with slow roll. A few were a fair bit 
>worse. The wrap terminations are at the same position (equal distant 
>from speaking bridge pins) at the bridge end, thus rendering unequal 
>wrapped speaking lengths.
>
>The work on this Baldwin F blew me away - it was "rebuilt" by a 
>company that is quite arguably the most respected in my area (or at 
>least best known because of brand affiliation).
>
>If you ordered a set of strings, installed them and saw this, 
>wouldn't you send the back to the string maker (after checking your 
>measurements again to make sure you didn't provide bogus data)?

Without seeing the soundboard bridge it's impossible to comment but 
the stringmaker's "error" is pretty regular, that is to say that the 
lower string of is consistently 3-4 mm further from the stud than the 
upper one, so it's not just carelessness.

Most grands have the soundboard bridge pins paired parallel to the 
stringing stud so that both strings have exactly the same speaking 
length and the same length of covering, and the copper line is 
parallel both to the stud and the line of the bridge pins, but the 
bridge pins on most Steinway grands are not paired like that and 
simply follow the line of the bridge so that the left string is quite 
a bit longer than the right one.  For looks alone, if for no other 
reason, Steinway strings are covered so that the copper is the same 
distance from the bridge pin each side and the same distance from the 
stud at the front.  This means that not only is the speaking length 
different but also the length of the covering.  If this has caused 
problems with tuning Steinways for the past 130 years, perhaps 
someone should let them know so that they can put things right!

JD




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