MacGyver Revisited
Use of a pneumatic suspension is popular in the industry. However this is seldom, if at all, properly implemented. Overlooked is taking into account the suspended weight and the spring rate of the suspension component. This is vital as it determines resonance. Now, if we are so careful about matching compliance of tonearm to cartridge (which determines resonance) it seems the industry left us to guess this resonance with their expensive elastic suspensions. The DIYer can easily do better, and the below equation should help obtain this goal of proper resonance. The template at the referenced website makes this even easier.
SPRING FREQUENCY CALCULATOR (NATURAL FREQUENCY OF A SPRING)
F1 = (1/2pi)*(k/M)^0.5
Reference