Jake Johnson wrote:About Tunelab and other EDT's using upper partials:
Since we can roughly calculate the iH of the strings, would it be possible to work backwards from the upper partial that is read? If we know the iH of a string and the freq of its 6th partial, can we come close to finding the fundamental? Or would the uncertainty about the exact iH of each string make the margin of error too wide?
Jake you are ready to make a tuning software !
THis is what is computed by all EDT's, and in a sense, by Moddart when building and Instrument.
Look at the "edit iH constants" window in Tunelab, you will have those readings, if some samples have been recorded, or none if you did not. Then you can enter 0.66 and , for instance, and look at the difference of pitch provided higher and lower of A4 (note49)
In the usual mode of display, under A4,the partial used is the 2nd, then the Third, then in the low bass it may be anyone from the 3 to the 12eme, as long as it relate to the 2 notes '(top note and bottom note of the interval tuned, an octave generally)
This is to allow more precision and to focus on the same kind of octaves (same size) that the ones traditionally used in tuning . ( octaves and intevals are named by their partial relation to have an idea of their "size in regard of the ih)
The higher partial relations are used to provide an "opening" of the octave. Then the fast beating progression of intervals is slowed, and it goes in the direction of what the human ear is asking, a higher treble (for the bass the lowering is due to the iH, so the partials of the bass notes relate well to the medium of the keyboard).
Many tuners tend to focus on one sort of octave by region of the keyboard, " listening at different partial levels and changing that partial match formula when descending/raising thru the scale. This is a well know method to have a little control on the stretch. Is it really accurate ? I would not say so, as what is the sign of a good progression is the quiet evolving of the speed of the RBI (Rapid beating intervals) such as the 3ds the 6Ths and all them with octaves added inside (17th 24 th..)
The sampling of iH is done in any case prior to a tuning, (to use an EDT) I did not mean that Tunelab cannot be used in the Bass in fact it may work fine with another partial displayed, one which is in the audible range of the sound card.
I've find it useful to have only fundamentals, essentially to have a fast view of what is heard or what is tuned, as it allow to see the real frequencies of the note at the screen, computed or tuned.
On my Pocket PC the fundamental may be heard down to D2 73 Hz (while singing I cant sing lower ! on a piano I recall it goes a little lower )
I f I where to tune a piano with Tunelab I would use the proposed partial set, for a higher precision in principle .
Last edited by OLEK (04-03-2010 11:22)