Danger!

[John M. Formsma]

Alan,

 

I don't think it's goofy, but it seems like nowadays so many folks is using
dem durn compooters fer ears that the thread might be dead before it ever
gets started. ;-)

 

I would always test so you know exactly where the 5ths and 12ths are. I use
the M6-M10 check for the 5ths, and the M6-M17th for the 12ths. In other
words, to test D3-A4, you'd play F2-D3, then F2-A4 and compare beat speeds.
You'd run into problems with pure 12ths in a small piano, and I'd guess that
the 2bps you were hearing in the Lester were coming from a wide 12th rather
than a narrow one. Dunno for sure, though. I'd also add a fifth note - A2,
so you can check the A2-A4 double octave, as it might suffer from a D3-A4
pure 12th.

 

Anyway, in ET particularly, we're always making compromises to make all
intervals sound appropriate. The issue is about what kind of end result
you're wanting. Yes, you can get the D's and the A's set as you describe,
but that might make other intervals (e.g., the E's as they relate to both
the D's and A's) less desirable, and it's totally dependent on how you set
them originally. In your example, if you set the D3-A4 at a pure or nearly
pure 12th, it will force the other intervals to be slightly wider to "fit."
Your A3-A4 octave will have to be wider than a 4:2 octave, somewhere between
a 4:2 and 6:3, which will make the double octaves beat faster than if you
used a 4:2 to begin with.  I normally like to tune with a slightly wide 4:2
A3-A4 octave (when the piano allows it), allowing for slightly faster
beating in everything but the 5ths and 12ths, etc. In other words, you
choose to favor the 5ths (and their combinations - i.e. the 12ths and 19ths)
more than the other intervals. There's nothing wrong with that in my book,
as I really like that sound, but you can get too carried away and forget
about the double octaves.

 

My goal is to balance out the piano as much as possible, and is a technique
I first heard about from Bill Bremmer on the list some years back. My aim is
to make the octave-fifths (12ths) and the double-octaves (15ths) beat
equally. Usually it works out to begin with a slightly wide 4:2 octave for
A3-A4. (Actually, what I'm listening for is the best harmonization of all
the partials I can hear, and is usually somewhere between a 4:2 and 6:3
octave.) I use an F3-F4 temperament octave, and as I go up from F4, will
tune octaves similar to the A3-A4 with which I began - just slightly wide of
4:2. At F5, you have the first double octave, so you can check for equal
beating with the 12th and 15th at this point. Normally in my tuning style,
this works out to about 1/2 bps or thereabouts. That translates to playing
F3 and F5, then Bb3-F5, and comparing the beat speeds. It's a pretty quick
check, and somewhat easier to listen to than the 10th/17th test as those
intervals get fast pretty quickly. You can reverse that for below F3. The
lower down in the bass it is, the harder it is to hear these beats clearly,
so I change over to tuning 6:3 and 8:4 octaves and comparing them to the
double, triple, and quad octaves to see how it fits.

 

This might be more than you asked for, but it might be a good start for
conversation. Or not.

 

John Formsma

 

 

  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Alan Barnard
Sent: Saturday, April 15, 2006 1:51 PM
To: Pianotech
Subject: Danger!

 

I've been thinking (that's the dangerous part) and doing some experiments.

 

When setting ET temperament on virtually any pianobig and nicely scaled or
Crappiola & Sonsthe 3rd partial of D3 ends up within about 1/3 Hz of 440.00
and almost always on the sharp side, like 440.26 Hz (440.04 on an M&H A). 

 

At this pitch, that turns out to be significantly less than 1/2 bps on
better pianos (almost pure) and the most I found was a little over 2 bps on
a Lester She-Who-Must-Not-Be-Named and that one almost certainly due to
compromises crossing the break.

 

Does this not, or should it not, have big-time implications for setting or
testing the temperament, as in a durn-near P12 at 3:1?

 

Fur eggs ample:

 

What if you tuned D3 to A4 at an exact or the teeniest bit flat 3:1 twelfth
(stick a mute alongside A4 keystick to hold it down, play and tune 

D4 beatless at A440), then tuned your D4 to A4 as a 5th, tune A3 to A4 and
compare to the D's and make sure you have two dandy octaves, 2 identical
5ths, etc? Would that not nail down four solid notes closely referenced to
your foundation A4, including the stretch across the break on smaller
pianos?

 

If this is goofy, be gentle.

 

Alan Barnard

Salem, Missouri

 

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