At 3:26 pm -0400 30/9/06, Farrell wrote: >...I.e. if a plain tricord has 160 lbs. of tension on each string, >there will be a total of 480 lbs. tension for that note. If you >consider then a wound bicord note, would you design each string of >the note to have 160 lbs. for a total of 320 lbs. tension on that >note, or would you shoot for a total of 480 lbs. tension on that >wound bicord note where each of the two strings would have 240 lbs. >of tension each? Neither of these solutions makes any practical or logical sense at all, as you could easily discover by measuring the strings of any half-decent piano. At the transition from trichords to bichords there is always an increase in the tension of the strings and a similar increase in tension is required at the transition from bichords to singles. For example a 6'6" piano with 12 singles and 14 bichord notes on the bass bridge might be strung throughout the plain wire at a target tension of 160lbs. The bichords might then be designed for 190lbs throughout with a jump to 270lbs at the top single. From there on down the tension might fall to 210lbs at note 1. This would be a pretty good model for a bass scale on such a piano. I omit to speak of core sizes except to say that a typical scale might have bichords wound on sizes 17 -> 19.5 and singles wound on 21 -> 24. The longer the piano the more choices there are for bass scaling. I quite often aim for 60% of breaking strain throughout the bass scale, which means that the tension in the bichords might rise from 180lbs to 220lbs as you go down. Most difficult and unpredictable of all are short grands, since these are most sensitive to variables in the construction and especially the soundboard. One often needs to sacrifice purity for volume by using stiffer strings, but then again there are exceptions, such as the 5' Blüthner. These are just elementary observations of a general nature. It is not possible in a short email to condense the experience of 20 years of bass string design and manufacture, not to speak of the 130 years of experience that preceded mine. JD
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