Due to floor trusses instead of conventional lumber I have about 16 inches of space in the ceiling of our new theater. Was originally going to use R38 batts in the ceiling, but will an R25 suffice? How about an R13 It's only for sound control between the basement ceiling and the floor. I'm not to worried about the R value.

Use the thicker stuff. It's to keep the cavity above from resinating also. The more insualtion, the more damping and the large the cavity appears acoustically (lower resonant frequncy)

Bryan

Should I use blown insulation then and completely fill the cavity. The R38 will only get about 13 of the 16 inch space filled.

Should I use blown insulation then and completely fill the cavity. The R38 will only get about 13 of the 16 inch space filled.

Blown insulation isn't worth it. R38 will be fine.

-drin