Will the placement of casters on speaker stands degrade the performance

@twoleftears’ suggestion is a good one. Use the Herbies until you find your permanent (ha!) speaker placement, then if you want remove them and install the footers of your choice. You can try the current rage---springs---without (heh) springing for the Townshend Seismic products. If you like what they do, start saving for the latter!

By the way, if you think moving around the 3.7i is hard, try a Tympani 3-panel model! Grant Mye makes a stand for the Tympani's, but they're not cheap.

Sure, there will be the question of stability with the large-frame speakers, there will be an acoustic effect as the speakers are lifted slightly higher above the floor, and MC's statement about problems with precise positioning on carpet is true enough. My opinion is that the positioning knowledge OP gains will more than offset those issues.

At the end of the day, I wager OP will have moved his speakers around more than many listeners who experiment with position and orientation. OP will be able to dial them in for his room, source, electronics, music preference, and so on. OP is tweaking and evaluating, and that's what the quest is about.

boing boing Miller, they said you would pop up.

If castors (sic, in the UK at least) have rubber wheels then they will behave similarly to your beloved far more costly Podiums - boing boing.

If you have a solid floor that it's a no-brainer - spikes or some other rigid interface will prevent your speakers moving.  If you have a suspended wooden floor then there is no set-up that will stop your speakers moving and smearing the SQ.

Not ’easy’ movement, ’just possible’ movement. Mine are well over 100 lbs. I have to pull/push pretty hard. They stay solidly where I put them.

Solution for movement needs to be made relative to the speaker’s weight and bottom surface area, and the floor material and solidity. Sitting solidly, so the woofer can’t rock the boat is the goal. Mine are 37 lb 15" woofers, on 3 hard plastic casters with tight axels, they stay put, Donna’s stuff stays put on the slanted top, and I can readily adjust toe-in to maintain imaging.

As I said, for ’just possible’ movement potential, forget spikes, they are a done deal for a single precise location, and any ’earth’ vibrations can/will go ’up’ to the speakers.

If you have lightweight speakers, they are small, and need to be up for tweeter height at seated ear level, thus stands. Fill the stands with lead, sand, make them out of steel beams, HEAVY, and firmly attach the speakers to the stand, now you own a unified heavy sucker. Now, a solution for ’just possible’ movement based on the weight and bottom surface area, and solve tipping potential.

Any bottom mounted material or wheel, I recommend 3, not 4, (more weight per contact area, self leveling). If tipping is possible during relocation, a skirt or rear corner blocks to prevent that.

Slip sheet on carpet; felt pads on hard floor; hard plastic casters slightly softer poly wheels; a bit softer rubber wheels.

Suppose an infinitesimal difference between spikes and your method of firm but possible movement could be measured by a scientific instrument. Lack of movement would negate improved ’situational imaging’ for the sake of an infinitesimal measurement, that’s a bad bargain. Further back, way back out of the way for table extension for family dinners is FAR more important, let’s get real, solve your life needs, the music will be more enjoyable.

Reading ’Townsend’s ’block earth’s vibration going ’up’, I recently tried to find softer surfaced casters. I tried, returned 3 different sets as each one’s ’soft rubber’ was far from soft. Finally I got some, switched them, the wheels axels were too loose, they wobbled: so the softer surface was achieved, but the big woofers could rock the boat because of the loose axels. Hard plastic with tight axels back on!

Mine are dual wheel, plate mounted (not post pushed into sockets) high quality furniture grade (moved from the Infinite Slope speakers (they found good ones). Some have optional brakes, not mine. If you need brakes, they move too easily.