I have a room in our new house designated exclusively for a home theater (my wife got a huge closet in exchange for my home theater), and need some advice on how to set it up. The room is 18’ wide, 28’ long, 8.5’ tall, and is completely underground (beneath the garage). Three walls and the ceiling are poured concrete and one long wall is just framed 2x4’s right now. My first question is: do I need to drywall any of the concrete walls/ceiling, or can I cover them as they are with acoustic panels? Also, do I use plywood, drywall, or something else to cover the 2x4 framed wall and other walls? I was planning on using as many acoustic panels as needed to cover the walls and ceiling, if necessary. Someone has already suggested filling the studs with acoustic insulation and covering them directly with sound transparent fabric, which is an interesting idea. I'm pretty handy and like to do most of the work myself, so I am open to anything. It looks like I can get 3 levels of seating, so I'll build the risers when the wall plans are solidified. I have some pretty good hardware (projector, screen, speakers, receiver, etc), and will probably upgrade several pieces once it is operational, but want to make sure I get the proper acoustics so it sounds as good as it possibly can, before hooking anything up or upgrading. Any help you can provide would be much appreciated. I want to get the walls all built and covered now, so let’s start there first. Also, I am not really concerned with having a visually appealing "theater look". I only want it to sound the best it can. Thanks!