[pianotech] Tunic Onlypure Tuner

Richard Brekne ricb at pianostemmer.no
Sun Mar 8 04:43:53 PDT 2009


Hi John.

A few comments interspersed below:

         You'll have to write Stopper to see if he is still selling
        aural licenses.

            This certainly extends the limits of incredulity.  A license
            to tune P12s????  No thanks, I'll pass. <G>

Yes, that was the general reaction when we all first heard about this 
earlier (around 2003) on CAUT and Pianotech. Even if you could 
realistically patent any aural approach, let alone one that has as much 
prior discussion, it would be impossible to control and not worth the 
effort and cost to patent to begin with.

    I had to tune my mom's piano today (Steinway M redesigned and
    rebuilt by Ron N). Fiddled around with how to do this. (It's not
    rocket science, but would take some time to think through it well.)
    I ended up just doing what I normally do. The end result is pretty
    darn close to all 12ths being pure anyway.  That's my preferred
    style: stretch the temperament as much as I can get away with
    without P4s being too busy.  Tuning open unisons helps it along,
    which is how I was doing it today.

Its not really hard to do. If you start off like I mentioned last time, 
you have four notes of 19 done. One approach is to take those inside two 
and tune P-12ths outside the temperament area to these, and then 
transfer them back inside the temperament area in the form of octaves, 
then continue around fudging as necessary to keep 4ths and 5ths 
acceptable. It insures that the initial temperament is good whilst also 
insuring that area is stretched to a 3:1 P-12th. The rest of the piano 
is easy. And yes, you can get close to all 12ths being pure even using a 
moderate stretch. Tho as the two graphs I supplied show things develop 
differently when you hold 12ths at a constant width visa vi some other 
interval. And you end up hearing this. Jim Coleman commented on this 
back in 2000 when I first started posting about how I was doing this 
with Tune lab 97.

    Though I wouldn't claim to know all about the science behind
    Stopper's methodology, I'm willing to wager that the end result is
    what many of us achieve every day ... by just listening to what the
    piano tells us it wants.  The Stopper details seem to be scanty, so
    we're left to guess a lot of what a Stopper P12 tuning sounds like.
    I did hear the one he did (was it Rochester?).  Sounded quite nice,
    but some things were not to my liking. The treble was a bit too
    stretched in the treble, and I'm one to do a stretchy tuning
    myself!  <G>  And there were some 12ths that were not pure. However,
    this may have been due to the pianos being sharp -- always so darn
    cold in those hotels -- and then drifting sharp after they had been
    tuned according to the ETD.  Also, things change as unisons are
    tuned. My mom's piano didn't have all the 12ths pure at the end of
    the tuning, though they all were during it. (It happens, as we all
    know. A better time to study the post-tuning intervals would be
    after a piano was tuned twice.)

Your comment about the treble is one I hear nearly every time, and 
indeed was exactly what Jim commented on back in 2000. Yet as I 
mentioned earlier, the highest treble C8 only ends up around 35 cents 
offset, which is moderate by any account. Thats because F6 resultant 3rd 
partial (after tuning it's fundemental to E#4's 3rd) is what determines 
C8's fundemental and this is rairly in this scheme far from 35 cents 
offset.

    So, those of you who have access to the OnlyPure ETD, some questions
    (and we'll assume a decent piano scale of at least 5' 8" in length):

       - Is A3-A4 generally between 4:2 and 6:3, and usually more of a 6:3?
       - Are P5s nearly pure in a "normal" temperament region? I.e., F3-F4
       - Are P4s beating a little faster than 1 bps in a "normal"
    temperament
       region?
       - As you are tuning the middle strings of the treble, does the double
       octave below beat about 1-2 bps until the other strings are tuned
    to it?
       Then, it decreases to just less than or equal to 1 bps? E.g.
    F3-F5, and I'm
       assuming tuning unisons as you go.
       - Does the bass go from a tad larger than 6:3 octaves to 8:4,
    then the
       lowest 5-6 strings between 8:4 and 10:5? (Except on very large
    pianos, which
       might be 10:5 or even 12:6)

I dont have his ETD, but my A4/A3 ends up fairly in between a 6:3 and 
4:2, and my D4/D3 ends up closer to a 6:3.  But this again depends on 
the pianos inharmonicity. Tho inharmonicity does not vary alllll that 
much in this area from instrument to instrument (good instruments that 
is)  it does vary some.  I never get much past 6:3 octaves and never 
pass 8:4 in the bass. Your middle question depends on which coincident 
pair you are talking about so I cant say right off. The 5ths I get are a 
bit slower then usual yes.

    Somewhere along the line, I think many of us end up at the same
    place while arriving by different paths. I'm certainly willing to be
    taught. But I'm not buying into tuning voodo. <G>

The P-12ths tuning does diverge from octave priority in a significant 
way. No doubt about it.  Tho it remains an equal temperament scheme. Its 
differences has to do with the beginning stretch imposed on its 
temperament region, and what happens the width of all other intervals 
and their partials types when you hold the 3:1 12th to a constant width. 
I think it was unfortunate that there has been so much use of the word 
"magic" tied to the whole thing. It's got nothing to do with magic and 
the association was/is I think counter productive at best.

    Also, I'm thinking this out loud.  I've heard that in Europe tuners
    prefer to tune more narrow octaves than we do here in the States. 
    Is this true?  If so, I've a sneaking suspicion that what Stopper
    might have done is simply expand everything from what is the normal
    in Europe. Any chance of this being the case?  In other words,
    instead of tuning 2:1 or 4:2 octaves for the temperament octave, his
    octave is between 4:2 and 6:3. Granted, he would have arrived at
    this by mathematical means, and I certainly applaud him for doing so!

I am not aware of any such tendency.  Stretch discussions are rampant 
here as well as anywhere else. In any-case  Stoppers work on the 
mathematics behind this and the basic concept of  P-12ths as a tuning 
priority has nothing to do with simply expanding on what otherwise is 
normal. My own suspicion, one that is re-enforced by finding several 
articles back into the very early 80s and no doubt beyond that is that 
at some point some folks started to notice that the particular aural 
octave test, i.e. Major 6th and double 10th could be used to achieve a 
P12th.  Baldersins book even declares this (and a couple other tests) as 
P 12th tests. And that somewhere along the line this started to gel into 
a tuning priority in itself. In 1982 an American named Gary Schulze 
published an article describing in great detail and defined his own 
version of the comma around P12ths and P19s. I will ask him if I can 
copy excerpts from a letter he sent to me about the whole thing earlier 
this year in a separate post. He cites sources for his work dateing back 
to 1943 by O.H. Schuck and R.W. Young, in J. Acoust. Soc. Am. 15; 1-11

    I personally think 2:1 octaves sound horrible, unless you're in the
    top octave, and have properly expanded everything below it. But even
    then, I like to go a bit above a 2:1.  So if someone has been used
    to listening to a piano tuned with primarily 2:1 octaves, there is
    no doubt in my mind that a P12 tuning would sound absolutely
    fabulous!  And I would indeed be proud of that "discovery"!  But it
    doesn't have to mean than no one else has been doing it heretofore.

    It is certainly fascinating, and I look forward to hearing more
    ...specifics.
    --JF

I think everyone agrees that 2:1 octaves are only good at the very 
top.... so there is no fundamental disagreement on that point. Nobody I 
know here in Europe does that. There IS a good deal of talk about not 
stretching the tuning...  but these folks who talk about that are not 
thinking in terms of coincident partials... and really don't understand 
that vocabulary at all. They speak of a "natural stretch" which ends up 
always equating to some resultant stretch based on some or another 
standard octave priority set of aural tuning  tests.

You'll note in reading Gary's note... that there are some very similar 
statements to things I've underlined all along.  Like how octave types 
converge in the base using this priority and how in the treble octave 
types get split right down the middle.

Hope this didnt get too long... but you put a lot of things on the table 
for comment :)

Cheers
RicB




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