Do you use spikes for tile/marbel floor?

Speaker spikes are almost always beneficial. The problem with tile or other hard surfaces is the damage the spike can do. The weight of heavy speakers, combined with their energy transmission during music sessions can literally "drill" a spot in your floor.

Sound Anchors makes stainless steel discs that employ Kevlar on the back side. Not only can these disks not be penetrated by any spike, the Kevlar does not store energy when working against rock hard surfaces such as you have.

I plan to use the Sound Anchors on my new floor, I have slate, which is hard but certainly vulnerable to the stainless steel spikes I use. For what it is worth, the Sound Anchor product was a Stereophile best buy recommended product. I think it is better to buy a few and listen first though, rather than follow only my suggestion or the magazine.

I use an extra tile or two with teflon gliders glued to them and spikes sit on top of that instead of directly to the floor. I use the spike cups also that hold the spike in place and keeps the speaker from sliding and also helps to absorb vibrations along woth the teflon rubber gliders underneath the extra tile . The teflon helps when you want to move the speaker to make adjustments - you do not have to take it off the extra tile. This helps to keep the existing floor from being scratched or dented by heavy speakers with spikes.

I am confident in believing that you should get some intermediate device. You would be a little hard pressed to find a speaker that would sound as good riding bareback on any type of floor. I have used audiopoint spikes and disks on hardwood floor and found that combination to work better than a spike/carpet combo, and much better than simply resting the speaker on the bare floor. Some have found good sonic results with Vibrapods as a replacement for spikes. They can be used alone without causing damage to your floor.