Key acceleration

[Don_Mannino@yca.ccmail.compuserve.com]

     Bob Hohf wrote:


>>    9.  the more mass on the front of the key, the wider the acceleration
envelope
10.  the less mass on the front of the key, the narrower the acceleration
envelope.<<

Bob,

Your message made it sound like a wide "acceleration envelope" is a good thing -
is this how you feel?  A wide envelope would mean the the piano would be easy to
control during soft playing, but would require much greater effort during ff
playing.

The addition of weight at the front of the key does increase the effort required
to accelerate the key for a big sound.  This is why I have always been puzzled
by people who feel that uprights should have more leads in the keys in order to
create more mass and make it feel better.

Expressed in your terms, it is my opinion that a smaller "acceleration Envelope"
would be the goal, with the position of the "envelope" placed as low on the
effort scale as possible.  This then could be used as an argument for reducing
the effective mass of an action, be either removing or relocating weight within
the system.

I'd suggest that a better name might be "effort envelope," and it could be a
useful and interesting way to describe one aspect of the "touch" of an action.
Not only the size of the envelope but the location on an effort scale should be
expressed.

Keep in mind that mass is only one part of the picture.  The leverages
contribute to the inertia of the system also, and must be considered in
describing the touch.

Don_Mannino@yca.ccmail.compuserve.com