DIY speaker isolation base for a wood floor

If there was no such thing as decoupling we never could have detected and observed gravity waves. The only challenge for decoupling for audio is how many directions 🔜 🔚 🔝 you can decouple from and how low a resonant frequency Fr you can achieve for each direction. My airspring Nimbus of yore, for example, decoupled in all six (count em!) directions with Fr as low as below 1 Hz. The lower you go the higher you fly. 
In other words decoupling is not (rpt not) synonymous with damping. Damping techniques on the other hand 🖐 cannot affect extremely low freqjencies of vibration. That’s why mass-on-spring devices must (rpt must) be used for vibration in the range 0-20 Hz. You can also think of iso devices as anti gravity devices, if that helps. By the time you get to 20 Hz you’re already 95% effective. So, where’s the beef? 🍔

When was the last time you had an in-room stereo Geoff?

Michael, Folks would generally be much better off if they believed in too much rather than too little. Would you believe I’m using mass-on-spring isolation right now? No, I’m not hot dogging you. 🌭 There are a great many advantages to small battery powered systems, as I’ve oft described. 

Me, I need to move mine:

Real Heavy Speakers on 3 Wheels. 3 = more weight per wheel than 4, and 3 is always self-leveling.

Current big box, 3 way, 15" woofer, horn mid, horn tweeter, I am guessing between 150-200lbs ea.

3 wheel caution. I have blocks just above the floor at the rear corners, the edge of the centered 3rd wheel, to prevent tipping, especially as they are tilted back as well. If it tips in any direction, the raised corner blocks then hit the floor, preventing further tip.

tilt: a concealed block at the front above the front 2 wheels tilts the speaker back, both time alignment and altering angle of reflections off the floor and ceiling.

Move to precise listening position, or push out of the way (some or a lot).

I've done the isolation/spike thing, with these, other 120lb speakers, and lighter ones. With enough weight I like wheels.

My JSE Model 2's, 125 lbs each, came with factory wheels.

https://www.google.com/search?q=jse+model+2&sxsrf=ACYBGNSrOb458uz5Jwdm0yyn06W5XsOqNw:1576775349791&tbm=isch&source=iu&ictx=1&fir=5zrM1YT0ijckLM%253A%252CuIXJGK1HDmXTvM%252C_&vet=1&usg=AI4_-kQ2cALZwZ45VVbDYcUebQJmdxiZWQ&sa=X&ved=2ahUKEwjNlfX0mcLmAhVrUN8KHeWzDPMQ9QEwAHoECAcQBg#imgrc=5zrM1YT0ijckLM:

Tried em, spiked em, no improvement obvious to anyone, so I changed 4 wheels to 3 on them. They had their own time aligned slanted front panel, and I just carefully avoided tipping. Loved them for many years, Son Chris has them now.

Thanks for all your opinions. When finances allow I might get those springs that Geofkait sells.