If they are a sealed or ported and NOT using a bottom passive radiator, you decouple the speaker, no matter what ANY manufacture says. The same way REL learned to make a model that is not bottom firing. They will also LEARN decoupling is what audiophilers do it stop unwanted passive floor, walls and ceiling resonance.
I quit using bottom firing subs that weren't slot loaded in the 80s.
I assure anyone on AG I been making Subs a lot longer than REL, a whole lot longer..
As long as REL sticks to that type of thinking they will find people that want the best won't be coupling a S812 to the floor.. EVER. Nice looking sub BTW
On the other hand if you like the WHOLE house shacking and stucco falling off your house by all means couple up nice and TIGHT..
Spikes work great on springs, pods or air ride. LOL Very simple to understand.. They been doing it for 100 years I know of with every piece of vibrating equipment on the planet.. What on earth makes people think a speaker is any different.. Dampening is the only way to stop thing from breaking.. Same with destructive harmonics.. You don't make bigger nuts and bolts and tighten them tighter, you dampen them.. Try the Flintstones Ride. Rock Rollers for tires vs your pneumatic tires for just starters, then springs and shocks and springs in you seat.
NEED I GO ON.. Springs not only work, they work extremely well for the cost vs improvement.
If you like jackhammers in your home glue them to the floor. Even the kids are spring mounting their bass enclosures.. and dampening the heck out of their rides with SR71 or Blackhole.. So who is smarter the kids or the Dads.. Dads around here listen.. :-)