Will the thinset mortar stuff damage speaker wires? What precautions might be necessary?

Also need speakers for 14x14x8 room, no sub planned, space for towers beside TV unit limited. I'm concerned about the M22s lack of bass w/out sub, but the M3s specs say they don't actually go any lower. Just a perceived increased bass response? Would prefer to stick with Axiom in case I ever go 7.1 downstairs. Any ideas?