Subwoofer Footing - Connect or Isolate?

Speakers and subwoofers like to be solidly mounted to add structure to the enclosure, they do not like to be in micro motion.
The ONLY reason you would ever want to iso mount a speaker or subwoofer is if the energy of the speaker is transfering into something such that it is audibly resonating, e.g. a suspended wood floor.
In that case you would introduce isolstion of some sort because not using it is worse than using isolation.
isolation is a compromise solution, the speaker is now in micromotion.   no isolation is always best if the speaker isnt causing something else to vibrate audibly.

Are there any subwoofer manufacturers who provide a set of tuned springs with their speakers?

@mijostyn --

The last thing you want to do is put a subwoofer on springs. At some low frequency it will start shaking. Vibration/shaking in any speaker equals distortion.

@avanti1960 --

Speakers and subwoofers like to be solidly mounted to add structure to the enclosure, they do not like to be in micro motion.

+1 to both. 

WOW, it makes me wonder if people pay attention AT ALL.

There is no solid anything in a conventional domicile.

I had to pour a 22" thick by 24" wide x 18 foot long to get a base.  Just to isolate gear correctly, and stop transfer from built in base traps. 10,500 pounds of concrete and a 5/8 rebar cage of sorts.. It is isolated from the 5.5 inch slab in the old metal shop.. LONG term project, LOL 33 years ago now. A really good concrete guy did the figuring a LONG time ago..
ZERO cost.. he paid for everything. REAL good friend.. RIP..

In Pete, sandy loam or bog forget it..  I can jump up and down and you can feel it 50 feet away.. 1/8 mile from my house it's just that way.. Tule Pete.

Regards

I'm with oldhvymec on this one. The only thing that made listening to my stereo system remotely tolerable was to move the house off its existing foundation, remove the foundation, excavate a 35' x 45' x 15' deep pit,
fill it with rock and rebar and pour a bazillion truckloads of concrete into the fill it. The new audiophile foundation cost me plenty, you can be sure of that.

That's why my REL T5 does not need special footers or even springs.