My couch didn't have much in the way of feet, and the bottom of the back is a board that runs the entire width of the couch. So I took of the solid feet, and replaced them with the rubber ones from the LFE kit. The ButtKicker is mounted on the plate that also came with the kit, and it is under the middle of the board in the back of the couch.
For low intensity bass it feels really good, but as soon as something explodes it's too jarring. Almost like something solid is being struck. I'm hoping that feeling is just because of the current mounting situation.
There are two beams that run the depth of the couch, they are about 2 feet apart. I'm planning on building a platform to bridge between those two beams. It'll be a rectangle of plywood, with 2x4s running the length of it. I'll glue and screw them to the plywood. Then I'll drill four holes in the beams, and pilot holes in the 2x4s to attach the platform to the couch with lag bolts. I'll also drill four holes in the plywood and make use of the ButtKicker mounting plate. So the plywood is sandwiched between the transducer and plate, and bolted together with slightly longer bolts than what came with the kit.
I'll probably swap out slightly taller feet than the ones that came with the kit too.
