Frank, There's no need to take a side - I suggested "also" checking C8, not "instead of". Seems to me with a mystery such as this Ibach, the more data points he can consider, the better. A quick scan of some scales for grands in the 5' to 6' range shows that targeting A49 at 415mm gives a range of about 3 notes. So does targeting C8 at 52 (wider range if you consider the S&S model S). So maybe looking at both notes will yield a little more certainty than just looking at one or the other. cheers Mike George F Emerson wrote: > Hi Paul, > > I have to side with Ron N. Measuring the length of A4 makes more > sense. On quick review of scales I have studied, the length of A4 > ranges from 400 to 429mm. 415 is a good median, but obviously the > shorter length (400) is in a spinet, and the longer length (429) is in > a concert grand. Judging where your piano falls in the range from > spinet to concert grand can give you a better length to target. Also > consider that the difference in length from note to note, at A4, would > be about 20-22 mm. > > Regarding C8, there is nothing sacred about a 60% break point. > Depending on the v-bar termination material, radius, and deflection > angle, a higher break percent can be tolerated in the highest notes. > To expect that the maximum length for C8 would be 52, just because it > exceeds 60% break point, ignores the reality that many scales > historically go well beyond this length. 54mm is not unusual, without > presenting any problems with string breakage, when mitigated by other > factors (mentioned above). This is a difference of only 2mm, but > the difference from note to note in this part of the scale is only 2 > or 3mm. Also, it is difficult to accurately measure shorter lengths > at C8, than at A4. > > Frank Emerson >
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