understanding the cause of irregular velocities

http://www.forum-pianoteq.com/uploads.p..._top_c.mp3

the above mp3 demos a group of notes (top E to top C [except Bb]) that I have calibrated precisely exact so that their velocity curves are perfectly matched. The beauty of PNOscan in conjunction with it's WinNessie/Midi9/PNOscan software is that this can be acheived, although it has taken me many hours. Each key's weighting had to be measured to give me a rough idea of how much compensation to apply per note. it has taken me a couple of days just to complete these - very time consuming. But you can readily hear the difference. I will add the midi file shortly so that anyone who wishes to may listen to it through different PianoTeq models. It will take me some time to complete the whole range, and I'm not sure I'll actually like it when I'm done, but it will be interesting to hear nevertheless. You are right of course about different players hands playing blacks/whites at differing velocities. It was a good idea of Fatar/Studiologic to implement a black vs white velocity curve adjusting ability in the way of YouPlay. However, being able to calibrate from the source is much more accurate and, as demo'd, can be set exact - although many would not wish to a) spend the time necessary to do this an b) play the result!

As you can appreciate from listening to the mp3, there is a certain sound that is produced when  velocity curves match exactly key to key. It certainly makes PianoTeq sound 'different'! I played this demo normally throught he keys, no editing etc.. Once all neighbouring keys are 'in', it sounds uniform even if you are not playing particularly evenly. I would be very interested to know people opinions as to the sound produced. Not everyone will like it, but not everyone will hate it either! Let me know your thoughts.

The only difference between the calibration needed to achieve perfect uniformity and the initial automated calibration setup are the necessary compenation overides possible via the software (available upon request from QRS to PNOscan customers) basd on the key weighting measurements. PNOscan, as with any and all sensor strips, are cuurently not equipped to measure how much force you are actually applying to any given key in order to produce the velocity which it can, and does measure as far as I can tell. The distance the key travels i.e. rest position to down position is measued also and velocity curves computed. This means that although, in the case of PNOscan, there is an extremely precise measurement of these via optical means,  friction differences and the like that vary from key to key causing one key to be more sluggish and another more freer mean varying results from key to key - not through any fault of the strip concerned.  Of course there can be dirt ssues, bad factory setup etc. etc., but even if a keyboard was calibrated as exactly as mine will be, take a key out and put it back and you'll get a different result.  So is it any wonder that, as we play our boards, take them apart, clean them etc., that calibration, no matter how well performed initially, is no longer accurate.

One last thing I'd like to mention. digital pianos/ keyboards are often touted as having "No need of maintenance nor tuning". While the latter may be true, the fromer certainly is not. Just as any mechanical device, whether used or not, through various climatic and enviromental factors as well as wear in usage, needs occasional (or frequent) maintenance, so also do digital keys. I only fully appreciated this after months of work on the current project. Again, no matter ho well constucted a piece of mechanics is, it will need 'some' maintenance during it's lifetime, especially if it is to be a prolonged one.

That's it for now. Time to get that midi file uploaded!

Thank you for your post John,

Let me know what you think of the mp3,

Best Regards,

Chris

I am not sure what I am listening to here. Everything is in the highest register (a place that rarely gets touched by me) so I transposed down a couple of octaves and tried a few presets in Pianoteq. I am not hearing anything that jumps out at me, but I will give it another listen.

Another thought...I had to swap a key in the C3-C4 range with one from the upper register because it was slightly warped, and therefore was sticking ever so slightly. As I looked into this further I noticed that not all of the keys are perfectly uniform. You can tell by looking at the left or right of the key to see how flush the 'ivory' is with the wood. On some keys the wood is recessed and the top sticks out a tiny bit. Because the key was slightly 'off' it was sticking ever so lightly and causing articulation problems for me. It's fine now, but I had to do maintenance on my keybed...lending to your theory.

There are a lot of variables to consider here, but I hope you can find a happy medium at some point and just enjoy playing!

Except for when the keyboard or sensors are faulty themselves, right?

Hello All,

Another cause of velocity irregularities concerns the makeup of the human hand.  In descending order, here are the digits listed in order of strength (in terms of being able to depress a piano key):

Strongest -- Thumb
Next Strongest -- Middle Finger
Third Strongest -- Index Finger
Fourth Strongest -- Little Finger
Least Strong -- Ring Finger

If you wish to play a scale with a sense of "velocity evenness", then you must consider that you press your (strongest) thumb with less intended force than, say, your ring finger.

* * * * *

Next, consider when one plays the black notes of a piano / keyboard, the fingers are naturally more outstretched than when playing the natural notes.  This, combined with the fact that black notes on a real piano are "shorter" -- that is, there is less "leverage"  (less mechanical advantage) available to depress a lever whose depressing finger distance is comparatively closer to the fulcrum (capstan) inside the piano's action.

All of these factors contribute to difficulty in achieving an evenness of velocity, even if the keyboard has uniform velocity response.

Food for thought.

Cheers,

Joe

Hello Greg,

I had forgotten that fact that balance pins are offset on grand pianos' keys! You are absolutely right. My last paragraph was an afterthought, written quickly -- after having written about the variable strength of one's fingers.

Cheers,

Joe