Verituner Update

[Greg Newell]

Mr. Carpenter,
    I still wonder about a few things. 1) How far off does a piano need to be
before double tunings are mandatory. 2) In what way, if any, is a pitch raise
feature employed and how does that work? 3) I use TuneLab and find that I can
get embarrassingly close in one pass on a pitch raise. Could the potential users
of your machine expect similar results? 4) I have become quite used to designing
a tuning and then tuning chromatically. I've heard that a piano can be more
stable this way. I then make changes (tweaks) at the end of the tuning. I will
make corrections during if there are glaring problems but that is usually not
the case with TuneLab. If someone like myself were to use your machine would
they have to tune starting with A4 in order to guarantee 440 cps for that note?
5) Given the chromatic tuning style would the Verituner achieve enough in the
way of measurements when starting in the bass? 6) Is there an optimum way to
tune with regard to order of notes tuned? 7) You have stated that the Verituner
is "comparable to or better than alternative ETD methods" and in several ads
have placed your machine above them. Can you give and facts to support this
other than feeling that your method is better than the others? Could one hear,
in a tune-off for instance, a demonstrable difference between the efforts of
your ETD verses the efforts of the 3 other prominent ETD's being sold today? Is
there a way you can quantify your results as being "better" ?

Still not convinced,

Greg

Dave Carpenter wrote:

> --- Greg Newell <gnewell@ameritech.net> wrote:
>
> > Mr. Carpenter,
> >     How is this possible? If notes are measured and
> > then tuned "on the fly" is
> > not the octave stretching changed also "on the fly"?
> > If this is true then some
> > notes will be stretched more than others and you
> > will have a very uneven scale
> > throughout because the tempering is in a constant
> > state of flux. Further, does
> > it solve for A-440 or is that subject to change also
> > based on what it hears?
> > Could you please explain?
>
> Greg,
>
> You need to consider the order in which notes are usually tuned. For
> example:
>
> 1. Tune A4 to Partial 1 = 440 Hz, as in aural tuning. Simultaneously, you
> measure the inharmonicity of A4.
>
> 2. Since you know the inharmonicity of A4, you also know much of the
> criteria for tuning A5; you know at least what it is going to take to get A5
> to produce your desired single octave width.
>
> 3. At this point you also know something about the inharmonicity of the rest
> of the piano (In fact, the SAT 1 used to base its entire tuning from just
> F4, not too far away from A4).
>
> 4. Next you tune A#4. Knowing where you might tune A5, you can choose an
> appropriate amount of stretch for A#4 that will smoothly progress on its way
> to your idea of the target for A5.
>
> 5. You continue tuning upwards. As you do, more inharmonicity measurements
> are made. This refines your idea of the inharmonicity of the rest of the
> piano, because now you also see at what rate the inharmonicity is
> increasing.
>
> 6. You go back to A4 and start tuning downwards. Same methods are used.
>
> As each note is tuned and measured, its inharmonicity measurements are added
> into a sort of forecasting algorithm that continually refines its idea of
> the inharmonicity for the entire piano. This algorithm considers the
> inharmonicity levels measured, the rate of changes from one note to the
> next, and the quality factor of the measurements taken.
>
> After each note, target tunings for ALL remaining untuned notes are
> recalculated. This tuning is based off the latest inharmonicity forecast for
> the ENTIRE piano, plus the actual pitches of the notes that have already
> been tuned.  Octave widths are selected based on goals set by user selection
> of a style, and individual inharmonicity measurements are used to smooth out
> the progression of interval beat rates.
>
> There are a multitude of other note sequences that could be used that may
> give the tuning calculator a better idea of the inharmonicity earlier on in
> the tuning process. One easy example might be: A4, A3, A3-up, A3-down. Of
> course the extreme case is to tune the piano twice. Many tuners regularly do
> this anyway. In this case, the entire inharmonicity picture is known before
> you start, for every note, and an incredibly smooth tuning can be
> calculated. Since the Verituner can save these measurements for later use,
> you can recall these measurements on repeat tunings and get a similar
> effect.
>
> Having explained all that, it is important to put this all into context. The
> One-Step Tuning feature was designed as a TIME SAVING TOOL which allows you
> to just start tuning (without a separate measurement step) and still get
> good results, comparable to or better than alternative ETD methods. In my
> experience, the benefits of measuring the inharmonicity of each note
> outweigh the benefits of measuring, say, a span of a few isolated notes and
> not knowing whether these readings are representative of their surrounding
> notes. Then in the cases where you want to go further and get the best
> possible tuning, you can use alternate tuning sequences, or tune the piano
> twice, or recall a previous tuning.
>
> Additionally consider this: if you tune outward from A4, the first few notes
> will have had the least benefit of knowing the span of inharmonicity in the
> piano. However, these are also the notes that are the LEAST AFFECTED by this
> lack of knowledge. That is, A#4 would only move very slightly if you changed
> your mind about the amount of overall stretch, because it is close to A4
> which is the one note that never moves. (If you really wanted to retune A#4
> later, there is a ReTune function that selects a new target for any
> previously tuned note).
>
> So, the short answer to the original question is that yes, the octave
> stretching is changed somewhat "on the fly", but the results of this are
> minimized because:
>
> 1. Earlier tuned notes close to A4 are the least affected
> 2. All notes are tuned based on actual pitches of previously tuned notes
> 3. The general octave stretch is based on the trend of all inharmonicity
> measurements taken, not each note individually
>
> Dave Carpenter, RPT
> Veritune, Inc.

--
Greg Newell
Greg's Piano Forté
19270 Harlon Ave.
Lakewood, Ohio 44107
216-226-3791
mailto:gnewell@ameritech.net