I am designing my new basement home theater and have been leaning towards using 2x4 sleeper construction with 3/4" OSB subfloor on top for my home theater and entire basement project.
The reason I am leaning this way is from having a previous home theater setup which had a simple floor of carpet with padding over top of the concrete directly. The issue with this setup was the complete lack of sound transmission through the floor. The bass impact from front speakers and subwoofer were completely missing at my seating position. When I later put the same setup on a first floor with traditional wood framing, I immediately noticed the sound transmission through the floor and made me feel more like I was in the movies and music, not just hearing them, but feeling them.
If I put in a sleeper floor, I will need to remove and rebuild my staircase to accomodate the extra 2 1/4" in floor height. I can only have a maximum variation in stair height between any two treads of 3/8" from what I have found. This is a larger under taking than I would hope, but fully within my capabilities and budget.
My question to the other home theater builders out there is if my last experience of a plain concrete floor was somehow incorrect and if people would recommend carpet over concrete? What has been peoples experience with and without sleeper construction and would the sleepers add other unforeseen problems such as resonances or other anomalies? I am also going to extremes to sound proof the theater room and wasn't sure if a sleeper subfloor that is not physically connected to adjoining rooms would help reduce sound transmission unlike the concrete floor which will join all rooms together regardless.
I have no height issues, 9 foot basement ceilings and only one soffit of 10" over the TV screen. I have no water or dampness issues and a cold floor is not my concern either. If I do a sleeper floor, I will put down plastic, then treated 2x4s flat, using a powder actuated nailer, attached to concrete and then screw the subfloor to those. I am on the fence about adhesive between 2x4s and subfloor if I even need to pull up the subfloor to run wires, fix water damage, etc. I also plan to build the walls directly on the concrete and then put the sleeper subfloor inside the rooms not quite touching the walls sealing the gap with accoustic sealant.
I currently have one JL Audio F113 and may get a second for the theater and have Thiel 2.3, 1.6, and MCS1 speakers.