Combining Partial Changes with Scaling Issues
Inaccurate partial changes combined with scaling issues, can create problems in tunings.
Robert Conrad, Registered Piano Tuner/Technician, Tucson, AZ
Inaccurate partial changes combined with scaling issues, can create problems in tunings.
A low 4th A4 Number just means that when the prime octave is tuned as a pure 4:2, the resultant 2:1 is also pure or very close to pure.
This procedure is for pianos whose 4th A4 Number is generally less than 2.0 c. When the 4th A4 number is less than 2.0 c., the prime octave’s 2:1 can be either expanded or contracted – based on what the prime 5ths dictate – and still remain less than 3.0 c. wide. Most of the time on these pianos, the prime 4:2 octave will be either wide or pure.
My approach to midrange tuning is minimal beating. I don’t want to stretch any more than necessary to get a pair of good sounding prime 5ths contained within the prime octave.
Though not absolute by any means, there is a useful ‘relationship’ between the prime octave width and the widths of the prime 5ths.
This system uses the relationships of the prime octave (A3/A4) to the prime 5ths (A3/E4 & D4/A4) to determine the ideal widths for both the prime octave and the prime 5ths. This relationship will be found using the A4 Numbers the 4th A4 Number, and ‘Templates’.