Fw: Electronic Sustain Timer

[Sarah Fox]

That would work! :)  Does it also do RMS levels, by any chance??

----- Original Message -----
From: "Ned Swift" <swiftspiano@hotmail.com>
To: <sarah@gendernet.org>
Cc: <pianotech@ptg.org>
Sent: Wednesday, November 20, 2002 7:49 PM
Subject: Re: Fw: Electronic Sustain Timer


>
>
>
>
> Hi Sarah
>
> Since you are considering Tune Lab, perhaps you might also consider using
> Power Tracks Pro Audio by PGMusic.  I use it in my recording studio for
> recording and editing music.  It has adjustable functions such as gates
and
> limiters.  Gates cut off the low volume while limiters restrict the high
> volumes.  It will also allow you to measure the time of the sustain and
you
> can look at the waveform.
>
> The approach is quite simple. Record the piano on you laptop or PC.
Process
> the recorded waveform according to your desired volume levels and then
read
> the counter for the actual duration of the waveform.  You can even go in
and
> look at the recorded waveform from start to finish or at any point that
you
> choose.  Since the waveform is recorded, you can even create a library of
> sustains on various pianos.  The cost of the program is about $30.  For
what
> it's worth.
>
> Ned Swift
> Lowell, MI
>
>
>
>
>
>
> This isn't nearly as complicated as it sounds.
> > >
> > > No, it's much more complicated.  I know because I have done it in
> >TuneLab.
> > >
> > > If you look closely at the amplitude variations that occur as a note
> > > decays, you will see that even if only one string is sounding, there
is
> > > still a beat-like variation due to the precession of the string from
up
> >0and
> > > down motion to its ultimate elliptical orbit.  Any falseness in the
> >string
> > > makes matters even worse.
> >
> >Your point is well taken, but my method actually takes that into account.
> >(Perhaps I didn't make a big enough point of it in the original post.  I
> >did
> >talk about it though.)  As both the upper and lower thresholds are
> >crossed, the beating will cause the timer to switch in and out (or
> >start/stop
> >/start/stop or "stutter," if you will).  The final time reading will
> >be a reflection of the total time spent between the threshold bounds.  If
> >the beating is the same at the low amplitude (amplified 40 dB) as
> >it is at higher amplitude, the jittering across the thresholds should
have
> >the same profile, and hence the demarcation of the "start" and "stop"
times
> >will "stutter" the same.  I don't know if I'm describing this clearly.
Am
> >I
> >making sense?
> >
> >The circuit I propose is *really* easy and lends itself well to repeat
> >measurements on many notes without time intensive calculations.  The
method
> >you propose probably also works well.  However, an electronic method of
> >rectifying and averaging somewhat avoids the problem of the entry and
exit
> >of harmonic components as their vibrational components "rotate" randomly
> >with respect to the fundamental.  Put another way, the peak profiles can
> >have weird beating patterns of their own, even when the RMS value of the
> >waveforms may be the same.  Of course only true RMS averaging would give
us
> >"the" answer, but simple averaging comes close.  Peak detection is the
> >worst.
> >I suspect this is a small point, though, and your method should work
fine.
> >Whatever works...
> >
> >I'll check out Tune Lab.  Thanks!
> >
> >Peace,
> >Sarah
> >
> >
> >
> >_______________________________________________
> >pianotech list info: https://www.moypiano.com/resources/#archives
>
>
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