Soundproofing your Home Theater with Dr. Bob

In today's hurried world, most people don't have the time or money to waste taking the entire family to the movies (up to $50 to $60 per shot) so why not build out a Home Theater in your garage, basement, or spare bedroom? The construction and soundproofing of a Home Theater is much the same as building a soundproof music studio in your home. The only major difference is that with a Home Theater, you are less concerned with sound coming into the Theater than you would be if you were doing recording or voice-overs.
The most effective method for building your Home Theater is to actually construct a room within a room. Basically this means framing out new walls within the existing room. This is a lot simpler than it sounds. If you possess tool skills and are better with them than "Tim Taylor" on "Tool Time", then you most likely are qualified to undertake this project. You will want to frame out new walls within the existing room, this is pretty easy in a basement situation, where at least 2 of the walls are most likely poured concrete or concrete block, and are generally Earthen backed. They need no soundproofing whatsoever. By framing out the room within a room, you are taking all of the negatives in the room that were working against your soundproofing endeavor, and now making them more friendly in the form of "dead air space". Dead air space (if it is sealed) is good soundproofer in itself, but you will still need a little more soundproofing horsepower if you plan to watch Star Wars or The Matrix (cranked up) in your new Home Theater. Once the new walls are framed out, it is time to soundproof. We have found that good batt insulation such as Roxul AFB or Roxul Safe which are very effective when placed in the stud or joist cavities. If you are unable to find the Roxul products, then use a good quality rock wool or mineral wool to fill the cavities. The next step would be to adhere a layer of American Mass Loaded Vinyl directly to the stud structure. Attaching the MLV directly to the studs or joists allows the vinyl to resonate or move with the sound. If the MLV is able to resonate, it will work to it's full potential and will give you the sound blocking required for a well-soundproofed theater. The MLV will be stapled (industrial air drive stapler) or nailed (using roofing nails with the large plastic heads) to the studs or joists. If you are able to over lap the seams that would be better, however, if that is not possible, you will want to butt the seams together tightly and caulk both the butted seams as well as the entire perimeter of the newly installed MLV. You want the MLV to act as a soundproof membrane on your walls and ceilings. Caulking and taping the seams is essential for to seal the MLV membrane. The caulked seams will also need to be taped with a quality MLV sealer tape before installing the new drywall. I recommend installing 2 layers of ½" drywall for all of the walls as well as the ceiling. Now if this becomes too costly then a single layer of 5/8" fire code drywall will be sufficient. This should complete the soundproofing portion of your home theater.
Finally, if you are installing 2 layers of drywall to your home theater walls, it is highly recommended that you apply at least 2 tubes of the Green Glue damping compound to the second layer of drywall. Simply lay out the second layer of drywall on saw horses and apply 2 tubes of the Green Glue to the back of the drywall and then simply screw in your new layer of drywall to the existing drywall with the Green Glue sandwiched in between. The Green Glue will dampen both layers of drywall and will also stop the sound of the home theater from flanking onto the walls. Once this is complete, you with then need to acoustically treat the room to give it the look and the acoustical properties of a real theater. We will discuss this in our next article.This is Dr. Bob....Out!!