On 1/25/2011 9:55 AM, Mr. Mac's wrote: > On Jan 25, 2011, at 6:50 AM, Ron Nossaman wrote: > >> … The alternative is finding the uncontrolled piano 30¢ off pitch in the tenor and low treble every single time we tune it, … > > Ron, > > Knowing that some piano makes are notoriously reliable for this activity, > I have never really understood why this is so. > This, as you expressed, occurs at the break from wrapped music wire > to plain music wire in the low tenor, > and occurs at the strut? break at the high tenor to low treble. > > Always have I dealt with this in the university I service every semester, > but I don't recall a reason ever being given, nor have I ever bothered to ask. > I've just accepted that's the way it is. > > So, I'll stick my neck out, Is there one? Yes. Oh, you want to know what it is? Low break%. The lower the break% of the wire, the more it reacts to minor tension changes. Low tenors, because of shortened speaking lengths to get them in the piano, are at a typically lower percentage of breaking tension than the high tenor. At the breaks, bridges that should have an abrupt enough dog leg to them to maintain the speaking length progression across the break - don't. The too short lengths on one side of the break produce a lower break%, and are more reactive. That's it. Ron N
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