ETD vs Aural Unisons

[Jim Coleman, Sr.]

As one who has been tuning SAT unisons a good bit of the time
I must remark that my tunings have improved. Not everyone can tune good 
SAT unisons. One needs to consider the moment in time in which the 
decision is made that the LEDs are indeed stopped. The same is true in 
using the RCT or Tunelab. In every piano there is a concern for the decay 
rate of a tone. This almost parallels the decay rate in frequency. If the 
tuning decisions are not made at the same point in the slope of the decay 
then the unison will not indeed be the best unison. When one is using 
the SAT, it is good to stop 4 LEDs so that any tendency to drift one way 
or the other will be more obvious. A similar care is needed when using 
the RCT and looking for the full blush. If you get a full blush at the 
beginning of the tone while tuning one string and then you get the full 
blush a second later in the decay of the tone on the other string, those 
two strings will not be in perfect sync. The same is true with the Tunelab
program which seems to be more sensitive than the RCT.

One might say that there is an artform in tuning unisons aurally. I like 
to call this voicing the tuning. One can tune a unison just barely out of 
sync so that the tone seems to grow slightly. This amount of deviation is 
not such that one hears a beat in the unison, but it IS the beginning of 
a beat. I haven't figured out how to do this consistently using the 
ETDs, but I believe it will happen eventually. At that point in time we 
could say that science has triumphed over art.

Frankly, tuning unisons by ear is faster than with the ETDs, but when I 
want the ultimate in precision, I rely upon the ETDs. Granted, one can 
aurally tweak beating individual strings to blend in the unison, but why 
not fix the string-bridge situation first?

One more point; Those of us who tune both ways know that we use a 
slightly different hammer technique in tuning aurally vs tuning with ETDs.

Jim Coleman, Sr.