[pianotech] ETDs and false beats

[Dean May]

Hi Keith

False beats is one area where I think Tune Lab really shines above RCT. With
the real time analog graph the false beats show up as individual peaks.
Usually, I pick either the dominant peak or the sharpest peak for setting
the intial string. The graph often shows what RCT hinted out. Many times the
dominant peak diminishes as you get it near your target and then another
peak takes over dominance. With RCT the wheel would slow (with ghosting) and
then suddenly start spinning flat or sharp again as another peak would take
dominance. I found it very frustrating as you were never sure exactly where
you were. With Tune Lab you can see it before your eyes and I can pick a
peak, or pick an average. 

I then tune unisons aurally, but I watch that graph to see the various peaks
come in and out of alignment. Usually there is a sweet spot where it sounds
the best and falsities fall be the wayside. Watching the peaks while
listening helps find that spot.  

And, John, when you are cranking out 5-6 Kimballs, Wurlitzers and Acrosonics
a day 5 days a week you don't fuss much with trying to eliminate false
beats. You just try to find a sweet spot.

Dean

Dean W May                (812) 235-5272

PianoRebuilders.com    (888) DEAN-MAY

Terre Haute IN 47802





-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Mr. Mac's
Sent: Saturday, January 29, 2011 11:32 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] ETDs yep the thread continues


On Jan 29, 2011, at 7:24 PM, Marshall Gisondi wrote:

> . So I was wondering how do the ETDs out there hanle false beats, and 
> how do they handle the harmonics in the bass section. .

Marshall,

False beats, ugh, are a nuisance.
The following are very general comments
   and what I have discovered for myself and are not meant as gospel:

Sometimes RCT handles these rascals all by itself.
Sometimes, hearing does the job.
Most times, I go back and forth trying to get the best blend,
   until I say, "That's it. You get no more time from me."

Many times, relocating the ETD becomes a necessary activity
   to get the best possible signal,
   just as much as relocating your head with ears attached
   takes place to hear the best beating activity.
No way out of that.

Now speaking to the treble area only:
There are times when more notes with false beats exist than not.
    (I have found small Lester pianos are notorious.) So I detune the ones
that tune relatively pure,
  so they will blend in with the notes that refuse
  to even remotely tune in relatively pure.

As to the harmonics in the bass, I'm not certain what you're asking,
   so I'll say this much.
The longer the string, ETD is from very nice to excellent.
The shorter the string, still darn nice.
Tuning a bi-chord with an ETD is not a good idea.

Sincerely,

Keith McGavern, RPT
pianostuff.kamcam.com=