Howard Towlson inquires about his Duo-Art playing too loud.  I changed
the springs on the dynamic regulators of my Weber Duo-Art to get
a "shallower" vacuum vs. expression level curve.  With the weaker
replacement springs I got a maximum vacuum of about 22 inches water
column.

This works fine, but was not what I was looking for.  I wanted quieter
soft passages, but changing the springs will not give you that.  What
I got was a piano that only gives half of what it's supposed to give.
I put the original springs back.

I might suggest if you want your piano to play more softly on the loud
passages, simply place the "normal-soft-dance" lever to the "soft"
position.  On my Weber, circa 1925, this lifts the hammers, accents the
accompaniment at the No. 2 expression level, and actuates the primary
regulator (modulator) to cut the vacuum in half.

Ray Fairfield