I'm ripping out some old linoleum and carpet from a (very dry) 1/2 exposed basement and putting down berber carpet tiles. The tiles are 12"x12" and self-adhesive.

I'm wondering if there is an easy option for insulting under the tiles. I've found a few sites talking about putting down 1" extruded polystyrene sheeting under laminate flooring but I'm not sure if it will compress under something more flexible like carpet. Any other ideas out there?