Cabbiendi-- overcoming motor cogging in DD is an issue as massive platters don't seem to be enough for most turntable designs. I believe belt drive motors with faster RPM set up their own rapid vibrations, which are either less detectable by human ears compared to a slowly-rotating motor, or possibly add pleasant distortion that makes music more satisfying. The belt also absorbs some of the vibrations.
It should not be too difficult to design an experiment measuring perceptual, audible differences between the two designs on the same chassis/plinth.
It should not be too difficult to design an experiment measuring perceptual, audible differences between the two designs on the same chassis/plinth.