This is my Bonus room located upstairs and over my garage. I built the room 4 years ago when the rest of the house was built. It was painted to be used as kids playroom. It is located upstairs across from 2 kids bedrooms.
2 years ago I moved the kids toys out and the theater in.
The knee walls and ceiling are blown in insulation. When the room was built I did not know it would be a theater so no sound proofing/acoustical precautions were taken into consideration.
We watch movies routinely with kids sleeping right across the hall. I was pleasantly surprised that not allot of sound gets out of the room. I think the reason for this is because its over the garage and the noise seems to be loudest in the garage.
Things I learned or need to change:
I went with DIY painted screen and built the frame out of PINE-- BIG MISTAKE
My screen is hung over the only window in the room so the air that enters the room thru window sill has warped the screen to the point I need to build another.
My suggestion is to use a wood or material that does not SHRINK/WARP.
I will be changing the entrance door to an exterior door with more sound proofing. Currently If we are watching action packed movies very loud, We turn on fans in the kids room to drowned out the sound a bit. Not a big deal.
The color of the room will be changed very soon to a Dark Olive and possibly screen wall black. With the current color , I get to much reflection of light and it distracts me.
I will be adding acoustical panels as well to the first reflection points. The room is about 28'X13'. Not good for sound considering its almost a perfect rectangle. It seems very bright to me. I believe acoustical absorbtion in the high frequencies will help. Then I will add Base traps.
I wish I added skylights when I built it. I also wish it were a wider room. But my whole family enjoys it allot.