"There is no such thing as decoupling in audio. That’s just a talking point from those who are dampening (1). Once you put your speakers in a room all the physics of that room and the speaker becomes one and the same (2)."
1: We are not dampening (to make wet ;-), we are damping (reducing the physical vibrations is a solid material). Those who contend hi-fi components are themselves musical instruments (a silly contention ;-) and should be left to resonate, are against damping. Those of use who don’t consider components music makers but rather music reproducers, are for it.
2: We need to make a distinction between the physical mass of a pair of loudspeakers from the acoustic sound they propagate with a room. Those speakers are ACOUSTICALLY inseparable from the room (the room is to the speakers as the speaker enclosures are to rear output of their drivers). That does not mean the speakers cannot be PHYSICALLY isolated from the surface of the room upon which they sit. Whether or not you want to separate them is another matter.
@blueranger, GK’s springs are ridiculously-low priced compared with all similar products (the Townshend Audio Seismic line, for instance), and a great way to find out if you prefer decoupling to coupling (spikes, cones) of your speakers. But remember, as Geoff has correctly stated here numerous times, spikes and cones provide isolation down to a not-very-low frequency (around 10Hz), and coupling below that frequency. And that frequency is not a single number, but rather the corner frequency of a 1st order (6dB/octave) low pass filter.