Compression ridges was :Do you dry the ribs, along with the board, prior to gluing ?

[Ron Nossaman]

You quit stoking the fire for a minute, and the darkness 
creeps back in.

A flexible treble goes "dink". The treble needs to be stiff, 
which is what the fish is for. The bass cutoff diminishes 
unwanted spurious resonances and makes the ribs shorter in the 
killer octave - to stiffen them.

Too stiff a treble shrieks, which adding mass cures. So an 
overly stiff treble that's mass loaded is highly functional 
while still being well above minimally adequate stiffness. 
That's a built in safety margin for future climatic aging and 
deterioration.

Too stiff a bass is thin and lacks fundamental. Too heavy a 
bass clangs. The bass works well when the assembly is light 
and flexible down there. The purpose of floating the bass in 
small grands, and moving the bridge to increase back scale 
length, is to add flexibility and amplitude of movement.

The use of mass loads on the low tenor or high bass bridge is 
an after the fact attempt to blend any existing tonality 
mismatch across the break if the builder didn't get exactly 
what he wanted with the design. Nobody's perfect, so there's 
make up.

Ron N