Coupling vs Decoupling


I’m new to this forum and have been doing much reading. I’m aware working with the room and equipment can produce dramatic changes in sound. One topic I’m lost with is coupling vs decoupling. When, where and how to apply each method to produce the best outcome?  

My current system is KEF R900 towers with matching center, R600C and surrounds, R300 and a pair of JL E112 subs flanking a Sony A1E TV.  The room is a bonus room approx 24’ x 14’ with all centered on the 14’ wall. 

Currently the towers are equipped with spiked plinths and subs sit directly on the carpet with their OE feet.  Any feedback about how to best manage acoustic vibrations and when/where to apply coupling or decoupling methods is greatly appreciated. 
jdeickhoff

@geoffkait - the idea of a combination to produce ideal results makes sense and is intriguing. Do you have personal experience with a product you’d recommend?

There is much to choose from for audiophiles these days in terms of isolation products. It all comes down to budget, the weight of the item to be isolated, and location of the item to be isolated, e.g., on the floor or on a rack. You could search for “audio vibration isolation devices” to get an idea of what’s out there.
The trouble with the Gary Koh article is that he didn’t consider mass on spring technology when discussing coupling vs decoupling. He only addressed viscoelastic “isolation” which is not really in the same ballpark. Mass on spring isolation for speakers happens to be a hot topic these days with at least a few Mass on Spring solutions available to audiophiles, including those from your humble scribe. Viscoelastic material is usually found in constrained layer damping solutions, which can be incorporated into mass on spring designs if desired. Kind of depends on what you’re trying to accomplish and how far you want to go.
@geoffkait - fair comment. I offered it not as a complete set of solutions but a starting point to understand the differences. Spring thing is good here (MinusK), at least under my turntable (~238 lbs with plinth).
I have my OHM 5000's on a homemade isolation stand. 4 aluminum cones with 2 granite slabs sandwiched with rubber and cork for dampening. I built a wood cradle around it so the speakers would be less likely to roll off. I have wood floors covered with carpet. 
jdeickhoff
the floor is a second story carpeted wood floor in a bonus room above the garage. The TV and components sit directly on a wood console
Always de-couple your speakers and equipment from a wooden floor even if it's carpeted, unless you want the floor to act as a sound board and ruin your bass.

Cement slab floor you can couple to.

Cheers George