[pianotech] ETD tuning during temperature changes

[John Formsma]

Interesting discussions currently going on about ETDs and aural tuning. I'll
not wade into those waters again ... at least this time. <G>

However, I have been curious about how ETD tuners deal with pitch changes
that happen with temperature changes. A good aural tuner automatically deals
with pitch changes in previously tuned sections when the temperature varies.
We are rather forced to, because we must refer back to previously tuned
sections as our "source" notes. I can hear how previously tuned
sections have changed, particularly at the tenor and first soprano breaks.
And I know it's not lever technique or the "usual" changes that happen.

In the following kind of scenario, what do you do?

Warm air blows across a piano for 10 minutes from the heater vent. (Or the
stage lights come on 15 minutes into your tuning.) This means what you've
just tuned previously will go flat from where it was.

With aural tuning, you have a sort of self-correction. Your "target" will be
a bit flat because your "source" was (e.g., tuning F5 from F4). When the
warm air stops blowing, everything will rise slightly in pitch, and things
migrate back to "right."

What about ETD tuning? An ETD knows nothing about pitch changing back and
forth from temperature variations. All it knows is that the note you're
currently tuning isn't "right" according to its programming. It has no way
to know if, in the past minutes, a string has just dropped 4 cents because
of heat. All it can do is display where it "ought" to be. So in the above
instance, when warm air has lowered F4 by a couple or more cents, and you're
at F5, it wants to put it at the "proper" pitch.  When the warm air stops
blowing, F5 will now become sharper than it should be, unless the tuner has
been monitoring and compensating based on what has already been tuned.  At
least that's what I suppose.

So how about it, ETD users?  What do you do?

It has been about 4 years since my last ETD use. I had tuned well aurally
for some years prior to that. But, frankly, with the Verituner, I watched
the screen, and didn't pay much attention to what had already been tuned. If
a change in temperature happened, well, there was still work ahead, so I
plugged away with watching and tuning unisons as I went, paying no mind to
previously tuned sections. (Shame on me, yes; happens to others, probably.)

Do you ETD users notice these changes? And, if so, how do you compensate for
it? Do you play octave combinations below the note being tuned to see what's
going on below it? Do you alter the tuning program with an offset of some
kind? If you offset, how does the program keep up with various offsets? Say,
if the heater stops blowing, do you then reconfigure the offset?

-- 
JF
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://ptg.org/pipermail/pianotech.php/attachments/20110127/e37b5ea5/attachment.htm>