In my opinion it depends on your room construction. If you live in an old victorian with a suspended hardwood trampoline floor then decouple, seismic retrofit or whatever. If you live in a concrete bunker or steel reinforced highrise then you have the option to experiment. With this scenario coupling makes sense, unless of course you want to enjoy your vinyl rig during an earthquake, then by all means decouple your turntable at least. I've lived in both and I'm currently coupling. Just use common sense before you get talked into the latest overpriced "it's like I bought a new amp" isolation component because in your situation it might be a total waste of money.
To couple or decouple? That is the question.
This is one of my favorite subjects and pet peeves.Is this just a matter of semantics or a misrepresentation of the principles applied in the set-up of equipment. My experience tells me that coupling is what you work for. This is the principle that is expoused in the early Linn literature. The mechanical connection that doesn't introduce or take away any information. This seems important with componets with transducers primarily turntables and speakers. Different materials, like sorbothane, are used to attenuate frequencies but are used in conjunction with metal cups to physically couple to your stand, shelf, floor, etc. Coupling also allows mechanical/acoustical energy to travel away from a componet. The designers at Mission in the early 80's were right on to this. Questions or comments please.