Sorry I clicked too fast before I had copied the message: There is useful information at
http://www.aquilacorde.com/faqi.htm However, I am not sure how to interpret the following : "Example: can I tune in A 440 a lute with a string length of 62cm? .62 mt (62cm) x 440 (Hz) = 272.8 Hz.mt The answer is: no, I can't. What should the appropriate string length be? A safe index should not exceed the 240 value. So: 240/440 Hz = .545 mt." I assume this must be speaking of an A lute, and that for a G lute at 440 Hz g-1 is at 392Hz, the diameter of 0.42 is not relevant, the tension seems to be 4K (Gamut calculator). I suppose for this string the breaking strain is .60 (mt ) x 392Hz = 261,072 Hz That would appear to be at the limit. Yet my top strings have been lasting 2 months (Nick Baldock). Have I got something wrong, here? Anthony Full text below: 14) What is a string's Breaking Index? The Breaking Index is the higher frequency a gut string of any diameter can reach at a string length of 1mt. For both gut and Nylgut a mean value of 260 Hz.mt is a good reference parameter. In other words, a 1 meter long string - gut or Nylgut - will statistically always break at 260 Hz, i.e. about 'C'. Hence we deduce that the product of the pitch of the treble and by the string length (more properly called 'Working Index') must always be below this value, under pain of immediately breaking the string at values over 260 or a very short playing life at values between 240 and 260. No problems below 240. What is its practical use? Example: can I tune in A 440 a lute with a string length of 62cm? .62 mt (62cm) x 440 (Hz) = 272.8 Hz.mt The answer is: no, I can't. What should the appropriate string length be? A safe index should not exceed the 240 value. So: 240/440 Hz = .545 mt. In practice the appropriate string lengt (at A-440) should not exceed 54 cm. Rule of thumb (assuming the system bridge-string-nut is free from any so called 'cutting effect'): - Working index within 240: green light. - Working index between 250 and 260: amber light (the treble could break in a few hours/days, especially by high humidity). - Working index over 260: red light (the treble will break immediately or within minutes). Le 19 juin 08 =E0 10:06, Andreas Schlegel a ecrit : > The breaking point of gut is around 250 Hz/m (some string makers > talk from 240Hz/m - and Mimmo give the breaking point for his very > strong type at around 260 Hz/m). > So a lute with 50 cm has the breaking point at 500 Hz. If you want > to play - instead of changing strings - you have to tune the > string around one semitone lower. > > Regards, > > Andreas > > Am 18.06.2008 um 22:48 schrieb Leonard Williams: > >> On occasion the topic of "authentic" pitch arises: to what >> G, e.g., >> was a lute tuned? Thre's that old dictum of tuning the treble to >> just >> before it breaks. So--my question is: What is the breaking pitch >> (frequency) of gut? >> >> Regards, >> Leonard Williams >> >> /[ ] >> / \ >> | * | >> \_=_/ >> >> >> >> >> >> To get on or off this list see list information at >> http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html > > --
