>>The few references I have read on scaling generally give the formulas,
>>and talk about a desired tension range of, say, 160-180 pounds.
160 lbs is OK for plain wire (trichords), but bichords should be higher, and
monochords higher still.
>>But I have learned that trying to stick to this tension in the tenor section
>>results in using very heavy wire, which, quite frankly, sounds like crap.
That's because as you increase the core wire size, you also increase the
inharmonicity, which was already too high.
>>I checked a Steinway M in the shop last week, and calculated the tension
>>on the lowest wire to be in the area of 120-125 pounds, obviously out
>>of the "desired range".
If you really want to fix this problem, you'll need to change the 4 lowest plain
wire unisons (29-32) to wound bichords. That is the ONLY way you'll be able to
get the tension up (to the point where the strings will sound good) while also
keeping the inharm down where it wants to be. I have rescaled 2 "M"'s this way
succesfully, that is - they had no discernable tonal break from bass to tenor,
and they still sounded like "M"'s.
>>How can I best determine the wire guage in this section of the piano?
>>Are there some "rules of thumb"? Or is there a good book available
>>that can help me with this?
You need to use a scale design software package, although you can use a
spreadsheet if you have the spare time to set one up. The important point is
that you be able to view the entire scale at once in order to achieve a smooth
transition of tensions and inharmonicities from note to note.
If you are a PC user, I sell such a program, as does Tremaine Parsons. If you
are a Mac user, then you're out of luck, at least as far as I know. Another
option is to use Dave Sanderson (PIANOBIZ@aol.com), who will do the design work
as well as fabricate the strings for you.
If you do elect to rescale this instrument, be sure to inform the customer
that you will be modifiying the string design. Also bear in mind that if you
have the original strings "duplicated", chances are that they will NOT be exact
duplicates anyway, so either way you will not be using the "original" scale. The
chioce is not whether to rescale, but rather who will do the design work!
Mark Dierauf
visit the WinScale homepage at:
http://www.ourworld@compuserve.com/homepages/mdierauf
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