[CAUT] back duplex

[Ron Nossaman]

>I was recently called out to a 7' grand with a buzz.  Names and brand will 
>be withheld to reduce my stress level.  It turned out to be the back 
>duplex.  There was so little bearing at the aliquot that the strings could 
>be moved back and fourth with a finger nail.  After much searching, I 
>finally found, (and a local tech who works on these a lot 
>suggested/confirmed) that when the humidity went up, the strings touching 
>the aliquot were raised enough to buzz (at center of piano, around F3).  I 
>called the factory and the tech said, sounds like a bearing problem, plate 
>position problem, etc.  Send it back, we'll send another.  I did.  Then, 
>when the 2nd piano came in, it had the same bearing problem, so I stopped, 
>did not prep, just called the factory.  The dealer then called a second 
>tech out who threaded a strip of felt through the back duplex to prevent 
>any ringing at all.  What effect does this have on the sound, etc.  I 
>figure, if it was designed to ring, it should.  Was this a good solution 
>and an ethical handling of the customer, who paid around $28,000?  Thanks.
>
>Lance Lafargue, RPT


What was/is the net bearing across the bridge in the area where the buzz 
is/was? And what's the soundboard crown look like in that same area?

Ron N