[pianotech] Beat Speed of 5th Decrease in Treble?

[John Formsma]

Jeff,
There are tests to help determine which partials you are hearing.  I'm
assuming you probably know them.  The most helpful one for me (for the 3:2
partials) is the M6-M10.  Say you're tuning F3-C5.  You'd play those two
notes with G#2.  And you can also "ghost" it to help the ear focus on the
correct partials.

I'd have to be at a piano to know whether I listen inadvertently to 6:4
partials.  I know I sometimes hear them if they're prominent, but constant
ear training helps your focus so you can avoid getting off track by tuning
with the 6:4 partials.

In my tunings, the P5s at the 3:2 level don't get faster in either the bass
or treble. In fact, they hardly beat at all.  But I tend toward a pure 5ths
tuning. Not quite, but close.  My tunings are somewhat expanded compared to
some, but that helps eliminate those nasty narrow P5s and P19s in the
treble.

--
JF

On Wed, Nov 5, 2008 at 11:11 AM, Jeff Deutschle <oaronshoulder at gmail.com>wrote:

> List:
>
> I have read threads where someone mentions that the beat speed of 5ths
> should decrease in the treble and that 5ths even become wide of just
> intonation. I have been trying to figure out how this could be, both
> theoretically and in practice.
>
> Theoretically, it seems that this could only occur if each octave was tuned
> more than 2 cents wider than the octave below it. In practice, my 5ths beat
> rate increases, not decreases, in the treble. If I try to stretch the
> octaves so that they beat slower, this results in unbearably busy octaves
> and 4ths.
>
> The only thing I can figure out is that the threads are referring to 3:2
> 5ths and I am listening to 6:4 5ths (which I believe I am). I imagine when
> taking into account inharmonicity that a 4:2 or 6:3 octave could result in
> the 3:2 5ths beating slower going up the treble while the 6:4 5ths beat
> faster. But then what about going down into the bass? Wouldn't the 3:2 5ths
> beat faster going down into the bass? That is hard for me to believe.
>
> So, can anyone one help me to understand this? I feel like there is a piece
> missing in this puzzle.
>
> --
> Regards,
> Jeff Deutschle
>
> Please address replies to the List. Do not E-mail me privately. Thank You.
>
>
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