This is a ButtKicker LFE “bass shaker” about to be bolted into my lounge chair.
A low-cost generic MOSFET plate amp drives it. You don’t need the over-powered matching Class-D mono amplifier. This plate amp only needs to be turned up to about 1/5 maximum and runs fairly cool.
I fitted pieces of neoprene “suspension” between the lounge frame and its feet to allow it to shake. The screws are left loose so the timber slides on their smooth shanks. It took a little fine-tuning (adding/removing neoprene strips). The expensive mounting kit was not necessary and is not as tidy.
It works really well to complement the subwoofers by extending into the infrasonic range very efficiently.