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Path: utzoo!linus!philabs!cmcl2!seismo!harvard!talcott!panda!teddy!rdp
From: rdp@teddy.UUCP
Newsgroups: net.audio
Subject: Re: tuning equipment..
Message-ID: <1055@teddy.UUCP>
Date: Tue, 30-Jul-85 10:33:09 EDT
Article-I.D.: teddy.1055
Posted: Tue Jul 30 10:33:09 1985
Date-Received: Thu, 1-Aug-85 20:12:05 EDT
References: <2437@mit-hermes.ARPA> <1277@hound.UUCP>
Reply-To: rdp@teddy.UUCP (Richard D. Pierce)
Distribution: net
Organization: GenRad, Inc., Concord, Mass.
Lines: 52

In article <1277@hound.UUCP> rfg@hound.UUCP (R.GRANTGES) writes:
>[]
>There are two different types of equipment that you could use.
>There is a type which makes the measurement just as you describe it
>and indicate the result on a meter which is calibrated to show
>sharp (+) or flat (-) in "cents" or hundredths of a whole tone.
>
Wrong, a "cent" is usually considered to be a hundredth of an
equal-tempered SEMI tone, not a whole tone.

>The second type generates a tone which you listen to while also
>listening to the instrument. You will hear "beats" between the two
>tones when they are close to the same pitch. The beats will slow down
>and stop altogether when the two are exactly together.
>
One of these instruments is called a tuning fork!

>
>I believe they generally are rather expensive for two reasons. First
>an accurate internal standard is necessary for either type to be of
>any value. Second, they are usually only purchased by professional
>tuners
>
FIrst, they are expensive because they must provide frequencies which
are not whole number ratios of one another. This is difficult to do
in digital (accually, it's impossible). For example, an equal tempered
major 5th has the "ratio" of:

			          7
                                 ---
                                  12
                                2

as a fifth encompasses 7 semi-tones. Therefore, the best that can be done
is an approximation. (Actually, the approximation can be had reasonably
accurately and cheaply via CMOS top-octave generators, which are, I think
a couple of dollars)

The second reason given, if true, could be restated: "They are expensive
only because people are willing to pay that price, because they are
'professionals'"

>  Of course "real professional tuners" use an old tuning fork
>and set the scale by experienced ear, then set octaves by beats.
>You can also set the scale by beats in a complex way I am not 
>familiar with (being neither professional nor a tuner).
>Good luck.
No, real professionals DO set the scale by beats, there are several
texts to explain this method for a variety of tuning schemes, which
I will post if there is interest.

Dick Pierce