Which is precisely why the A0 - C88 method of tuning with an ETD should be
avoided and some level of aural checks should be employed throughout if
accuracy is the goal (which, in all fairness, it sometimes isn't). There
are always outlier sections, the bass/tenor being the worst and the point of
that transition tends to vary from piano to piano. Also, the bass itself on
SAT machines, for example, is not actually measured. Nevertheless, I
continue to use an ETD and hybrid method of tuning and find it beneficial
for some of the reasons previously stated.
David Love
www.davidlovepianos.com
-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Ron
Overs
Sent: Tuesday, April 13, 2010 2:01 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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