I have brass cones presently & yes they'll certainly mark your wood floors. Haven't tried the BD's under my speakers although I do have pairs of 3's & 4's around for experimentation. Mainly I just want to suggest that if brass or aluminum is your cone of choice for best sound, then those little saucer-shaped cups placed under the spikes will alleviate the floor markings while not degrading the cone-coupling effect in my experience.
