Dark Grey convuluted foam

I'm still experimenting with the Auralex. Instead of glueing the foam directly to the wall I bought some 2X4 foot acoustic ceiling tiles from Home Depot and glued the foam to the tiles. Easy to mount the tile to the wall and I can move them around until they are placed correctly.
For bass tuning I cut the tile down the middle and mounted four foam pieces to it. This piece goes nicely into the corner.
Man k.d. lang sounds good right now.

Timrhu, good tip. Thanks everyone .
I just looked at the web site and it stinks!
I mean, I was not able to find anything as to the price of the products. I hate that!
The room calculator was nothing more than giving the web site my name,home adress, and email. The calculator then would not work !
Also, I could not find any mention of the Roominator kits.

How did you guys know what to order?
Must I find some dealer in order to find out these things?

Check Guitarcenter.com for pricing. I believe shipping is free if an item is more than $100. There may be a local Guitar Center near you. I never heard of them until I checked into the Auralex products. They had the kits in stock. My "Roominator" kit was $139 (I think). I have quite a few pieces left over but unfortunately I glued most of them to the acoustic tile. I figured I'd use them all but they can really deaden a room. Now I have leftovers.

check this out http://www.guitarcenter.com/shop/navigation?q=auralex&x=0&y=0

Thanks!