Relationship of terms, was Important Question, was lucky break

John Ross jrpiano@win.eastlink.ca
Thu, 19 Sep 2002 18:16:38 -0300


Hi Alan,
Just having an oscilloscope, is not going to help. You need an
interface to change the mechanical vibrations to electrical signals,
that the scope can read.
In fact you would need 2, and a dual trace scope.
I suppose 2 SAT's would do and feed in the filter outputs.
Or am I misunderstanding, and you just wanted to know, if someone had
a scope.
Yes, I do, left over from when I used to repair electronic organs,
5-10 years ago.

Regards,
John M. Ross
Windsor, Nova Scotia.
jrpiano@win.eastlink.ca
----- Original Message -----
From: "Alan R. Barnard" <mathstar@salemnet.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: Thursday, September 19, 2002 12:37 AM
Subject: Relationship of terms, was Important Question, was lucky
break


| Aha, aha, aHA! That's where I'm going with this ... how do Hz,
Cents, and
| Beat Rates all interplay?
|
| Does a certain percentage (cents) of distance between two tones
determine
| the beat rate without regard to the Hz of those tones, or does it
change
| with scale location, i.e., frequency?
|
| Unisons: Small changes in the treble area make a very fast beat
because the
| frequency changes drastically, compared to strings in the bass BUT
what we
| call "cents" is obviously proportional and/or exponential to
frequency
| because any given difference in cents means much a higher difference
in
| frequency (Hz) in the treble than in the bass.
|
| Anyone have an oscilloscope?
|
| Experiment: One string of a bichord base note at, say, 110 Hz
Fundamental (a
| theoretically perfect A3) and its companion string at 111.1 Hz. This
is a
| one percent difference. Is that one "cent?" What is the beat/roll
rate?
|
| Now compare that to two strings in the treble, one at 2093.004
| (theoretically perfect C7) and another in that unison at exactly
2113.934
| Hz--also a one percent difference.
|
| Will those two misaligned unisons each beat at the same rate
exactly? Does
| each pair differ by the same "cents" if they differ by exactly the
same
| percentage of Hz?
|
| Is my brain just spinning cobwebs, or does anyone else wish they had
a
| clearer understanding of the relationships of these terms?
|
| Alan R. Barnard
| Unraveling in Salem, MO
|
| ----- Original Message -----
| From: "sid blum" <sid@sover.net>
| To: "Pianotech" <pianotech@ptg.org>
| Sent: Wednesday, September 18, 2002 8:59 PM
| Subject: Re: Important Question, was lucky break
|
|
| >
| > ----- Original Message -----
| > From: Kevin E. Ramsey
| >
| >   "  Well, Alan, unless I'm wrong (In which case I'm sure I'll
hear about
| > it), in the area of the upper temperament, the difference between
A440 and
| > A441 is approxiamately 4 cents, so 442 would be eight cents sharp.
| >     That being said, one cycle at A0 would be about 64 cents at
the
| > fundemental level, according to Jim Coleman Sr. So I suppose that
one
| cycle
| > per second at the top of the piano would probably be a fraction of
a cent.
| > Just this month he mentioned that, and remarked that it gave a
whole new
| > light on lower bass tuning, and quibbling over a few tenths of a
cent. "
| > ********************************************************
| >
| > This reminds me of a thought I had recently while reading various
posts
| > relating to ETD s.  Would it not be useful to have an ETD that
could also
| > read out in the language of frequency (cycles per second)?
| >
| > I'm way over my head here, but I'm thinking a device such as this
could
| > relate to beat rates.
| >
| > sb
| >
| > _______________________________________________
| > pianotech list info: https://www.moypiano.com/resources/#archives
|
| _______________________________________________
| pianotech list info: https://www.moypiano.com/resources/#archives
|
|



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