cool, so is that cheap stuff at walmart a better deal than buying that akasa pax.mate stuff? i was thinking about that stuff and perhaps putting a panaflo l1a into my antec powersupply that came with the sonata.
It is making a difference for sure, but I don't have a frame of reference to compare it with anything else so it's hard to say if it's the way to go.
I think you will find even if you go to the Home Depot, RONA etc. that you can get plain old carpet underlay (also called rebond - try to get 10 lb weight if possible, 8 is all RONA had when I went there) and it will be about the same cost as the sleeping pad.
Most of the gurus in here are saying the "open cell" nature of the rebond makes it a better bet for sound baffling. Maybe in time I'll be able to confirm or deny this hypothesis through experimentation.
My new theory is that focusing on quiet fans (and if feasible replacing fans with heat sinks) is a must because either way you must have an air intake and an air outtake which means you have pretty much 2 big holes in your case for sound to travel out of. I would say focus on this area first, then get pick about the foam material for your case.