Vibration isolation or absorption?

Like almost everything involving vibration damping/control, it is a matter of tuning, so there is no definitive answer.  I've tried various speakers on damping platforms (the entire bottom of the speaker is in contact with a platform designed to transfer vibrations to the platform where the energy is dissipated as heat) and also tried the same speaker with spikes designed to transfer that energy to the floor.  In some instances damping the energy sounds better (tighter bass), in others, transfer to the floor sounds better (excessive damping can make some speakers sound lean or "dry" sounding).  It is really a matter of trial and error and personal taste.

Generally speaking, if you have a suspended wooden floor, and the bass sounds a bit boomy or muddy, decoupling from the floor would help.  If you couple with spikes, vibration is transferred from the speaker to the floor which acts as a sounding board that may make this energy more pronounced (and also delayed in time).  

What works best for any one person depends on so many factors that I find the best advice is to try different approaches.

@larryi +1, Spot on!

Mike

I’ve done no spikes/spikes, no difference, gave the spikes to my friend. His positioning/toe-in is ’stuck’, i.e. he cannot make any toe-in adjustment when I visit and we both are off-center. Wonderful imaging when centered is gone.

I believe in easily adjustable toe-in, solved relative to the speaker’s weight:

a. normal toe-in, central listener, both speakers aimed directly at center chair, and tilted so tweeter is aimed at seated ear height. tilt alters the angle of reflection off floor/ceiling/walls,

b. cross-field toe-in for two listeners, both off center: nice little drink table between the chairs. I have a wood floor with grid, very easy for me to go from a to b back to a.

aim left speaker directly to right listener. aim right speaker directly at left listener. You get pretty decent imaging, hearing both l and r: because: you are nearer to the speaker that is not aimed at you; and to far speaker is aimed directly at you. It’s about nearer volume matched with directly aimed volume.

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solve movement relative to weight:

1st, use only 3 contact devices, so that there is more weight per contact, and no tilt/wobble issues as 3 always finds wobble free position.

light-weight, 3 pieces of felt, sized to just allow movement when you apply force.

my speakers, very heavy 3 way horns/15" woofer/heavy cabinet:, I use 3 wheels, dual wheel furniture casters (because their axels are tighter, no wobble than very expensive single wheels I tried). 2 front, 1 rear, sized so the speakers move, but don’t move.

See photos of my virtual system. Plenty of Donna’s treasures on top. No movement of either her stuff or the speakers.

btw, single wheel in the back: anti-tipping must be solved. My JSE’s, flat bottoms (come with 4 wheels) I changed to 3 and had corner blocks just shorter than the wheels, tall speaker starts to tip, corner block stops it.

current, wood skirt conceals wheels, and the skirt is the anti-tip solution. Photo of speaker laying on it’s face, back off, in Virtual System.

Note: front, 2x4 flat above front wheels is what aims the tweeters up to seated ear height (why I went to skirt base) .

@emergingsoul 

I view this as 'points vs squishies'.

Points are used to move vibration into the mass to which the point is pointed. This is an old principle- I had an LP mastering lathe made about 1950. Its anti-vibration stand used adjustable points for feet.

Squishies are used to isolate- this is to prevent vibration from something else (like a shelf) from entering a piece of equipment (like a turntable). 

Platforms are supposed to be good at vibration absorption so usually the equipment placed on them has points that bear on the platform's surface. But it might have squishies beneath it to isolate it from a vibrating shelf or the like.

Speakers are supposed to be kept still so its common to see them use pointy feet.