Yesterday I tuned a 6-month-old Pearl River upright (EU118S). Prior to tuning, the owner said that she heard some sort of buzzing or rattling from one or more of the notes right around the bass/tenor break. I listened and while I did hear something, it didn't sound like any clear buzz/rattle to me - I thought it might just be the bad unisons.
So I tune it. She listens and still complains of noise at the bass/tenor break. I listen and yes, there was what sounded to me like a little bit of imperfect unison noise (shame on me!). So I work on those four notes around the break (the two lowest tenor notes are wound bicords) and clean up the unisons so that they sound pretty darn good to me. She still hears noise. IMHO, she was not hearing imaginary things, but I think she was also being super critical. She may also have been hearing the difference between the lowest plain-wire tenor note and the first wound strings. I did hear a little more noise that I would expect from a very clean plain-wire tenor unison, but relatively speaking, I would say it was a pretty clean bass string unison. Communication was difficult because she speaks little english. Her piano teacher set up the appointment. So I call the piano teacher (she functioned as a translator) and explained all about my understanding of bass strings and string noise. She seemed to understand my explanation and related it to the piano owner. She seemed happy afterward and even gave me a $$ tip.
My question here is really that I'm looking for opinions on the nature of bass strings and associated noise. I have found that (at least in the tenor) plain wire strings are seemingly fairly easy to manufacture to consistent specifications - and thus, as long as unisons are the same length and bridge pins are solid, tenor unisons can usually be tuned quite cleanly. Bass strings can be another animal all together. Some will tune nice and clean, while others will not uncommonly have partials that don't line up well and will always have some sort of beat (noise). I tune quite a few Yamaha C3s on the cruise ships - most are 10 to 15 years old and I'd have to say that at least 25% of the wound string unisons can not be tuned cleanly. I have noticed that Young Chang bass strings seem to have a higher propensity of bass string unison noise than some others.
So why do bass strings make undesirable noises? My guess is that the nature of the copper winding just makes it a bit more difficult to manufacture two strings exactly the same - same mass of copper, same tension on the copper winding, etc.
Am I missing anything major here? Is my thinking up to par? Please educate me!
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Terry Farrell
Farrell Piano Service, Inc.
Brandon, Florida
terry@farrellpiano.com813-684-3505
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