Since the harm from floor-borne vibrations are negligible in comparison to the far more harmful air-borne and internally generated vibrations and resonance it is actually a very good thing to direct couple the components to the racking system.
In other words, if you did not direct couple the components to the rack, where do you suppose the air-borne and internally-generated vibrations and resonance captured by the components in a moment in time but only disapate over a period of time would go?
However, it's really a moot point considering the design of the rack you describe since it is on casters (not appropriate for direct-coupling) and since the rack was probably designed for nothing more than perhaps an industrial look, computer server consolidation and convenient and controlled access.
Moreover, the rack walls and access door may also rattle at louder listening levels thereby making a bad situation worse.
I would suggest that you not attempt to rebuild your otherwise nice system around this rack that was never intended for this purpose and that will probably induce more sonic harm than what you had previously.
-IMO
In other words, if you did not direct couple the components to the rack, where do you suppose the air-borne and internally-generated vibrations and resonance captured by the components in a moment in time but only disapate over a period of time would go?
However, it's really a moot point considering the design of the rack you describe since it is on casters (not appropriate for direct-coupling) and since the rack was probably designed for nothing more than perhaps an industrial look, computer server consolidation and convenient and controlled access.
Moreover, the rack walls and access door may also rattle at louder listening levels thereby making a bad situation worse.
I would suggest that you not attempt to rebuild your otherwise nice system around this rack that was never intended for this purpose and that will probably induce more sonic harm than what you had previously.
-IMO