Spikes for very heavy speakers

Andrea II at 215lbs each - they come with spikes but my question is..... Since I will be placing them in my basement which has concrete slab....should I first get a small piece of thick solid wood...say 1inch think and place them on such a wooden platform or do you think it is OK to have the spikes direct on the concrete.... 
My only concern is of course that under such weight and no normal flexibility like you get with wood floors or even thick carpet - the tips of the spikes may bend slightly or the surface may chip making the speaker unbalanced / uneven...
I am not talking about significant crack or anything like that... but say even 1/16inch "dimple" 

thanks !