G'day all

I have a 1920  5' 6'' Steck Duo-Art in need of re-restoration which I hope
to do before long.  In the meantime, I have been tweaking it up to get the
best I can out of it.  One of the things I have noticed is that in adjusting
for very soft playing the bass notes tend to drop out sooner than the treble
side, apart from the unevenness due to other problems (valves and piano
action).

I am aware that some D-A actions (not mine) had graduated pneumatics,
presumably to provide more power for the heavier bass hammers, but this
doesn't seem to be common on players in general.  Because of the much larger
bass hammers, I would have expected this to be a universal problem but it
doesn't seem to be.  The effort needed to lift the base hammers would of
course transfer finally to the strings to produce the same loudness of the
note (theoretically) because the kinetic energy should be the same, less
friction, (greater mass but lower velocity).  I suspect that the problem
arises when the friction losses on very soft playing cause the heavy hammers
to fail before the much smaller treble ones.

My questions are:

   How serious is this problem in general and why isn't it more noticeable
   in other players?

   Is it more of a problem with grands where the motion of the hammers
   is working directly against gravity?

   Does it imply that the friction losses on my action are too high or
   am I expecting it to play too softly?

   Is there any simple solution to the problem? (the graduated pneumatics
   must have been too complex and voicing will only work when the note is
   struck fully and will likely alter loud playing too).

The accompaniment suction is the same for both sides of the stack so it
can't be done with the roll coding and any base side throttling would
soften loud playing, not soft playing.

Does anyone have any suggestions please?

Cheers,
Darrell Clarke
Adelaide, Australia