Disklavier

The paper I was thinking of is:
http://www.iua.upf.es/mtg/mosart/papers/p35.pdf

There are variations of the paper that were presented to different 
audiences, but I haven't seen any later studies.

Regards

James


George F. Litterst wrote:
>
> Good evening, everyone.
>
> I believe that the emails below are long on rumor and short on fact.
> I would love to read document in which Yamaha states that "that they
> can control the solenoids with 1024 levels but realistically get only
> around 256 distinguishable levels" or the studies that "have been
> done that show playback accuracy of player pianos is not as good as
> you would hope."
>
> The Mark IV Pro has an extraordinary record and playback system.
> Based on the reactions of the various Piano-e-Competition juries that
> I have observed--which include musicians of the highest calibre, I
> believe that the instrument has a practical resolution that exceeds
> what the average listener can perceive and that it is at least
> adequate--if not more that adequate--for the most discerning musical
> ears.
>
> As a pianist, I also believe that the Mark IV Pro can outplay a
> human--meaning that it can play faster, softer, and more even that a
> human.
>
> When making judgments about any particular piano, it is important to
> make sure that the instrument is in excellent regulation and is
> properly calibrated. If you are sending it MIDI data from an external
> source via a MIDI cable, it is important for it to be set to Delay In.
>
> Regards,
> PianoBench
>
> On Nov 14, 2006, at 6:26 PM, James Fry wrote:
>
> >
> > While varying levels of dynamics are important, I think far more
> > important than increasing the number of levels is the timing accuracy.
> > As mark says, the action wasn't designed with this application in
> > mind,
> > and I find it hard to believe that
> >
> > Studies have been done that show playback accuracy of player pianos is
> > not as good as you would hope - there was a paper somewhere
> > (possibly in
> > the archives?) which compared a mark II disklavier to at least one
> > other
> > system and found that there were great timing inaccuracies when the
> > velocity was varied. Given how important small timing changes are in
> > other areas of audio, I wouldn't mind betting that it makes quite a
> > difference with pianos too. It would be interesting to see how the
> > Mark
> > IV compares to previous versions of the disklavier.
> >
> > Regards,
> >
> > James
> > Mark Fontana wrote
> > On Mon, 13 Nov 2006, Carl Youngblood wrote:
> > >
> > >
> > >
> > > I'm sticking to the "mechanically impossible" statement, adding the
> > > reasonable assumptions that the piano is not in a vacuum and uses a
> > > standard grand escapement action, which just wasn't designed to
> > achieve
> > > this level of precision.
> > >
> > > Yamaha's own admission that they can control the solenoids with 1024
> > > levels but realistically get only around 256 distinguishable levels
> > > already leads one to extrapolate that achieving beyond ten bits of
> > > playback resolution is unlikely... adding more input bits isn't
> > the answer
> > > to overcoming mechanical limitations.
> > >
> > > PianoDisc mentioned at the 2006 NAMM show that they have a high-res
> > > playback system in development, and it uses ten bit expression
> > levels.
> > >
> > > Wayne Stahnke's Boesendorfer SE system is ten-bit.
> > >
> > > Boesendorfer's new CEUS system is ten-bit too.
> > >
> > > Ten bits appears to be the practical upper limit for this
> > application.
> > >
> > > Regarding the amplitude resolution of human hearing, these links are
> > > interesting (though more casual than scientific):
> > >
> > > http://www.ethanwiner.com/BitsTest.html 
> <http://www.ethanwiner.com/BitsTest.html>
> > > <http://www.ethanwiner.com/BitsTest.html 
> <http://www.ethanwiner.com/BitsTest.html>>
> > > http://www.pcavtech.com/test_data/ 
> <http://www.pcavtech.com/test_data/> <http://www.pcavtech.com/ 
> <http://www.pcavtech.com/>
> > test_data/>
> > >
> > > Mark Fontana
>
>