I've found the idea that speakers need to be rigid coupled to prevent the loss of transients isn't the case at all. At least that's my experience with some hefty bass drivers. I have open frame (ie no baffle) 15 inch bass drivers. These cover 18Hz to 110Hz in my system. The drivers are wired in reverse polarity and face each other so the cones travel in the the same direction, not cancelling out forces.

The interesting part is that the drivers are suspended by steel wires. The drivers are free to move - totally the opposite to normal practice. I was skeptical this could work as intuitively you'd think when bass kicks in the drivers will move and wreck the leading edge of notes. The reality is that this does not happen. I can perceive no physical movement of the spiders. Bear in mind that with all the bass cancellation involved with open frame there an enormous amount of power feeding these drivers...(900W per driver - yes I use 2 stereo class d amps to power these). Even on really bass heavy material such as Kraftwerk - The Man Machine - the only movement is from the cones - [U]massive[U] excursions. The bass is easily these the best I've had and pretty much the best I've heard.

IMG_20180525_221445 by Clive M, on Flickr