Disklavier

James Fry wrote:
> On Sat, 22 May 2004, Robert Welcyng wrote:
> 
>There are papers on Citeseer, such as Goebl & Bresin (see
 > http://citeseer.ist.psu.edu/585474.html) that show midi velocity vs 
dB SPL
 > for a Mark II grand. Their plots show an increase in SPL of staccato 
notes
 > between 100 and 120.

REW: James, I assume you are referring to the graph of Figure 4 in the 
paper written by Goebel and Bresin.  Those graphs relate the sound power 
output to the measured (by the DKV) MIDI note-on velocity when the 
instrument is played manually.  Note that keys struck with a velocity of 
about 100 produced SPLs of about 100 dB and that notes of up to 110 SPL 
were produced manually.

Now look at the graph of Figure 5.  The manually played notes of 100 SPL 
  (which ideally would have reproduced at 100 SPL) actually reproduced 
in the range of about 92 to 102 SPL.  You can see the limiting effect in 
that area of the graph where the still louder original notes were not 
reproduced proportionally louder (meaning a greater reproduction error).

A graph that might have better depicted the Disklavier's limiting at 
higher velocities, had it been included by the authors, would be a plot 
of the SPL errors in the reproduced notes versus the velocity values of 
the corresponding notes.

Bob




>>Just for the record, the highest possible MIDI note-on velocity is 127 
>>decimal, and the lowest, 0 (note-off).  (Velocity values are represented 
>>by seven bits within a Note On Message. The binary number 1111111 equals 
>>2^7 - 1, or decimal 127.)
>>
>>If a note of velocity 90 does not damage your DKV, then neither will a 
>>note of velocity 127.  The reason is that the designers of the DKV have 
>>built in MIDI-velocity-limiting.  With the DKV Volume Control set at 
>>"0", a note of velocity 127 will strike the strings no harder than a 
>>note of velocity 90.  Therefore, you need have no special concern about 
>>the source of the MIDI file, be it PianoDisc, QRS Pianomation, 
>>electronic keyboard, or found on the Internet.
> 
> 
> Is that really correct? I was under the impression that the limitation you
> hear is due to the solenoids running out of power, but I am probably wrong
> on that. There are papers on Citeseer, such as Goebl & Bresin (see
> http://citeseer.ist.psu.edu/585474.html) that show midi velocity vs dB SPL
> for a Mark II grand. Their plots show an increase in SPL of staccato notes
> between 100 and 120. What a MarkIII or Pro can do I have no idea.
> 
> 
>>However, I believe most of us would agree with Carol that there is 
>>little benefit, mechanically or musically, in driving a DKV to the 
>>maximum.  Before playing a newly acquired MIDI file, take the precaution 
>>of reducing the DKV Volume Control to its minimum.  That has the effect 
>>of setting all note velocities to about 25.
> 
> 
> I'll agree - it's not worth driving the DKV to its maximum. On my MPX1Z
> (Mark IIXG U1) the DKV volume control depresses the soft pedal and I don't
> think it does anything to the note velocities. If I play something
> energetic back then you can still see the mechanism being tortured -
> obviously on the grand's it wouldn't have quite the same effect. That
> said, the solenoids aren't capable of producing the same velocities that a
> human could produce at the keys, so it's no different to someone sat there
> bashing away is it?
> 
> Anyone know why Yamaha appears to have implemented the system differently, 
> or if I just misinterpretted what was happening when I lower the volume 
> control on my piano?
> 
> Thanks
> 
> James
> 
> 
> 
> To Post a message to the group, send it to:   disklavier@...
> 
> To Post a private message to Todd Muncy, the group's founder and moderator, send it to:
> disklavier-owner@...
> 
> To reach our group's web site go to:
> http://Yahoogroups.com/group/disklavier
> 
> Todd's family web site was completely updated 012/22/03.  It contains some fun disklavier content and links to midi sites among many other things, The url is:
> http://MuncyFamily.com 
> 
> THINKING OF LEAVING THE GROUP?
> If you are thinking of unsubcribing because you are getting too much mail, go the the web site and change your email delivery option instead.  That will fix the problem, while maintaining your access to the group.  If you insist on leaving us completely send a blank email to:
> disklavier-unsubscribe@... 
> 
> Know someone who wants to join?  Have them send a blank email to:
> disklavier-subscribe@... or give them this link:
> http://Yahoogroups.com/group/disklavier/join 
>  
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 


-- 
Robert Welcyng
Anchorage, Alaska