The other effect to take into account is inertia. The movement of the driver cone(s) has to move air to create the sound ....air has very little or zero effective mass therefore it's inertia (resistance to movement is low) unless you are in a totally sealed room.
There will be an effect based on the drivers area, hence smaller drivers are deemed faster as the volume of air they are displacing is lower, but this is also why (in general) the lowest frequency they can produce is higher and why bigger drivers need more power - think of the same sized engine trying to drive a mini at 70 mph or a large removals van.
The mass of the speaker itself will have a greater effect as will the rigidity of the cabinet. In order to get the vibration conducted from the driver into the speaker cabinet to have an effect on the sound it produces the energy needs to overcome the mass of the cabinet in order to get it to move ....the higher the mass the more energy needed to move the cabinet (think of pushing that mini again - or the furniture van).
Panel flexure can have another more complex effect particularly on low end reproduction ( more energy in low Hz frequencies). But if you could build a cabinet out of std A4 printer paper you would see the effects of the pressure waves from the rear of the driver cone move the paper sides with each bass thump etc.
Regarding flexible isolation mounts the more flexible (and undamped) the mount and the lighter the cabinet potentially more movement of the speaker body could occur on the mounts and this would reduce the perceived power of bass notes etc (and for any flexible mount its prime effect will be on lower end issues) and a faster response amp/power delivery will also have an effect as it accelerates the driver cone(s) quicker overcoming the inertia in the speaker/mount setup.
If you don't have neighbours etc and could split your speaker setup the ideal configuration would be heavy bass cabinets with large drivers ( mine are 18" and 250 lbs 😀) and the midrange etc in seperate enclosures mounted on springs/flexible mounts (to isolate them from the high energy bass notes being transmitted into the midrange driver which would cause it to oscillate with low frequencies as it was reproducing midrange frequencies) to reduce/stop smearing of the midrange.
The current use of such flexible supports is to stop bass frequencies travelling through floors etc into adjacent rooms and/or cause suspended floors to act as a 'boom box' and impact on the low end reproduction, and it is this that can make the sound 'cleaner' ....on a solid floor the effects should be significantly lower or even nil.
The reverse use of this sort of technology is in buildings like the Bridgewater Hall (concert venue in central Manchester) which was built on top of a sprung platform - not to isolate the concert from the surrounding area, but to stop the low frequency noise from the tram cars passing by entering the building and being amplified by the walls etc - a sort of speaker in reverse.
Hope my early morning ramblings help/make sense