MY ETD IS MADE BY SIEMENS

[william ballard]

On Mar 20, 2006, at 1:37 PM, Ric Brekne wrote:

> I seem to remember reading somewhere that it was around 30 hz.   
> Very iffy.

Iffy, in that it depends on the musical training of the listener? Or  
is it a matter of the mechanics of the inner ear? Do we need an  
audiologist?

>> Is the point which beat rate is too fast to     be unusable for us  
>> aural tuners any higher than 12 bps? Maybe that's     another  
>> measurement for an ETD.
>
> Definatly not.  You can use 15 - 20 bps no problem.

I may having been thinking of the visual, when apparent motion  
between two alternating blinkers becomes a blur. As for the aural,  
it's definitely above twenty, but I can't tell how much higher be  
cause of the equipment I'm using. (I made a percussion chart for  
clave in Finale, subdividing various note values into 4,5,6 and then  
on. I noticed that varying the metronome during playback in varying,  
there was a point at which the speed of clave clicks didn't seem to  
pick up speed and that seemed to be somewhere around 20 bps. Probably  
due to the low-speed midi software internal to Finale. A drum machine  
would do a better job.

> That is to say if you are comparing two intervals in which the  
> reference note yeilds roughly 20 bps for both intervals... an aural  
> comparison is easy enough to accomplish.

Are you describing the situation for a 10th and a 17th where the 2:1  
beat rate between the two upper notes is 1bps, and all three notes  
are high enough in pitch that the 10th might beat @ 19 bps and the  
17th 20bps? And the tempo difference between the two rates would be  
noticeable?

Anther way to run that experiment would be to use a contiguous mi3d/ 
M3d as in the 6:4 5th test, in the middle of the piano so the partial  
tones would be louder. Say, mute out 2 of 3 strings on F3 (that's  
amur'can, y'all) and C4. Tune that 6:4 fifth ± at 1bps. Now mute out  
the LH string on G#3, and temporarily muting out the middle string  
also, tune the RH string of G#3 pure to C4. The mi3d between this  
string on G#3 and the F3 will now beat at one bps.

Now increasingly flatten the center string of G#3, and the beat rates  
of the mi3d and M3d will increase, but the difference in their beat  
rates will remain at 1bps. On up to 19 and 20 bps  
respectively......and maybe beyond.

A drum machine could certainly do this better.

What I'm getting at is this. If at A440 (A4), 1 bps is 4¢ and if we  
take 20 bps as the maximum practically usable beat speed, then a beat  
rate range of 20 bps would cover 76.95¢ towards A#4. If we're now  
using that same 20bps range up at the top of the 7th octave, to tell  
us how close to a pure 2:1 octave we have between A6 and A7, that 20  
bps now translates to a ±9.81¢ window  within which to set octave  
widths aurally. Because of quick decays, 20bps might even be reduced  
by half.

Lots to ponder, I hope this threads continues on in an illuminating  
direction.

Bill Ballard RPT
NH Chapter, P.T.G.
wbps at vermontel.net

"Trust me, you've got all the equipment, You just need to read the  
manual"
     ...........Reese Witherspoon in "Legally Blonde"
+++++++++++++++++++++

-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20060320/0b48c3a6/attachment.html