What matters most?

[Mark Davidson]

I just knew someone would go practical on us.

Have to agree though.  You're not REALLY going to increase topweight
inertia, decrease key inertia AND keep friction, BW, compression,
etc. the same.  Perhaps at best there's a small range where one couldn't
perceive the changes.  And even if you could keep them the same, you'd
then have a different weight hammer hitting the string resulting in a
different
sound.

So maybe the question is what actually CAN be perceived.  How small
a change in hammer weight, bw, key inertia can be made before it is
perceptible.  Pretty small for hammer and bw - on the order of .1g and 1g
respectively.  How much for key inertia?  Do you put your weights close
to balance rail, key front or in the middle?  What if you're off by a cm?

So here's a more controlled experiment.  Setup two keys the same.
Then add 2 equal sliding weights in front and behind balance rail on one
key.  Move them apart (maintaining BW) until you can perceive a
difference.  Other things you could do with this setup: measure the amount
of DW required to get the same dB output with different key inertias.

-Mark

Michael Spaulding wrote:
>Bill,  I have to disagree with this.  Because the coupling of the key to
>the top action is compliant (wippen cushion, felt bushed action centers,
>knuckles, flexible shank), there will be a distinctly different feel to the
>two cases.  In the case of a key of average inertia with a top action of
>excessive inertia sitting on top of it, as the key begins its downward
>motion, the full inertia of the top action will not be felt immediately, as
>the compliant coupling starts to compress.  Whereas, with the key of excess
>inertia with a normal top action sitting on top of it, the excess inertia
>will be felt immediately as the key begins to move.  You can feel the
>difference.