[CAUT] using as ETD

[Porritt, David]

Ron wrote:  " The ETD uses the fundamental to determine the pitch, and will not be 'listening' to the fifths, fourths and tenths which will be annoying the aural tuner at the break transition."



Your observations about the hockey stick bridges and inharmonicity jumps are totally correct.  However no ETD that I am aware of listens to the fundamental in the hockey stick area.  SAT is listening to the 4th partial, TuneLab is flexible and can listen to any partial the tuner determines, but I'm not aware of anyone setting TuneLab to listen to the fundamental in that area.  My choice was the 3rd partial in that area.  The Verituner supposedly listens to multiple partials though I've never used one so I can't verify that.



Listening to the 3rd of 4th partial seems to help that area to be somewhat less bad that if it really were listening to the fundamental.



I still believe that once you solve the puzzle on a given piano it's nice to be able to save that solution for next time rather than solving the same puzzle over and over.  Before I retired from SMU my life consisted of maintaining 106 pianos.  It was quite a time and energy saver to pull out a saved solution for subsequent tunings rather than tuning as if I had never seen the instrument.



dave





David M. Porritt, RPT

dporritt at smu.edu





-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Ron Overs
Sent: Tuesday, April 13, 2010 4:01 PM
To: caut at ptg.org
Subject: Re: [CAUT] using as ETD



Jim wrote;



>. . . and truthfully, sometimes the ETD just ain't right! I've got a

>SATIII and a Verituner and especially at the break I'll occasionally

>disagree with the machines. I really don't know why, and maybe the

>real good ETD guys can tell me, but sometimes I hear strong beats

>that are objectionable . . .



I'm strictly a 'fork basher' Jim, but I'd like to follow up on your

observation. The ETD's stretch calculation is based on the

inharmonicity following a geometric curve, which certainly doesn't

happen at the break when a hockey stick long-bridge is incorporated

into the 'design'. When tuning down towards the shortened speaking

lengths of the hockey stick, the rapidly falling tension will result

in the inharmonicity rising up, away from the geometric curve of an

idealised scale. The fifths will appear to be increasingly narrower

than they are on account of the sharper I(3) in the lower note of the

fifth - when checking the fifth, or the I(5) when checking the tenth.

The aural tuner will compensate by slightly widening the octave to

achieve an acceptable beat-rate progression. Similarly, when the

lower inharmonicity of the first covered notes are encountered,

especially if the first covered strings are on the hockey stick, the

aural tuner will tend to make these octaves slightly less wide, to

prevent the fourths from beating wildly. The ETD uses the fundamental

to determine the pitch, and will not be 'listening' to the fifths,

fourths and tenths which will be annoying the aural tuner at the

break transition.



If a technician can't tune a piano without the help of ETD, it will

be most unlikely that he/she will be capable of obtaining an accurate

tuning with one. Especially at the break of some pianos.



Its amazing how some technicians, who use ETD, claim that their

tunings will, by virtue of the machine, be superior to an aural

tuning? Ironically, it gives me an indication of the aural tuning

skills of any ETD-technician who makes such a claim.



Ron O.

--

OVERS PIANOS - SYDNEY

    Grand Piano Manufacturers

_______________________



Web http://overspianos.com.au

mailto:ron at overspianos.com.au

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