On 1/12/02 8:47 AM, "Clyde Hollinger" <cedel@supernet.com> wrote: > Friends, > > How many of you ETD users do aural checks? Isn't that a waste of time, > if you can trust the ETD? Or can't they be trusted? (I'm not giving my > opinion -- yet, anyway.) > > Clyde It is not that ETD's are untrustworthy, it is that pianos are untrustworthy. Modern ETD's are accurate to within +/- 1/100th of a cent. Pianos cannot be tuned this accurately because pianos do not produce musical tones whose frequency is as stable as that. Compared to some other musical instruments the sounding tone of a piano note is very stable in frequency. However, if you read a piano note with a modern ETD, you _can_ see ups and downs in the frequency in the ETD display. Such ups and downs in the visual display can be the result, for example, of wildness in the string that results in more than one frequency at once coming from the string that the ETD must try to read at once. This means that the frequency display of the ETD needs to be interpreted by the intelligence of a human. The wildness can be so much that the display is rendered beyond interpretation, as in the example given by Ed Foote of the note that simply must be tuned aurally instead of visually. Many notes will yield a _little_ uncertainty that will be in need of a little interpretation. I suspect when techs say they don't listen at all when tuning with an ETD, there is an assumption that this is a piano that they have tuned many times, that the piano is very clean-tuning, and that the tech has a standard, consistent, practiced way of interpreting the ups and downs of the frequency display. The interpretation necessary when tuning a piano string to an ETD display is a common potential source of inaccuracy in tuning, and is a reason why aural checks are mostly always necessary. If you do your best aural tuning and record the tuning to an ETD and then at some future time use the stored tuning to tune the same piano again, is the result an aural tuning, or a visual one? If you didn't listen, I say the tuning is a visual one. All tuning done with an ETD should be subject to aural verification. Kent Swafford
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