Should I use Speaker Spike / Isolation Base or Something?

You want to couple the speakers to the floor.
IsoAcoistics will decouple as will any soft things like springs.
For a night and day improvement go with Stillpoints Ultra Minis. They screw into the speaker.
They will couple and turn the vibration to heat. But the movement of the drivers will stay in the box and not be drained into the floor.
You will need 6 x $100. They will be $25 less each since you don’t need the bases. I have them on my 190 lb speakers and the effect is transformative. The best $600 you can spend.

@clearthinker,I used the Triton Refs floor spikes and went with the GAIA II instead as I felt they were a bigger improvement.  The GAIA carpet spikes are cups with metal protruding to grab the rugs, they are not spikes persay.  The footers sit inside the cups which grab the carpet.

Another vote for the IsoAcoustic Gaias. Marten loudspeakers have teamed up with IsoAcoustics for their higher end models.

@stereo5
Your speaker will still be wiggling around and muddying the transmission of your sound.
Blowing in the wind.

@miglik   Your speakers too will be blowing in the wind if you don't couple them to something solid.

The issue is to prevent the speakers oscillating relative to your ears in the listening seat.  That oscillation will oscillate the sound you hear.
Simple physics.

Try not to listen too much to MC.

Noted MC isn't coming in on this.
Boing boing!