I have to second Mojo's comments.
Same thinking that we had and similar application, though we added more batts due to our 12" joist depth.
Sound decreases near 30dB from the media room to upstairs (actual music playback testing), if i recall. I think i posted the numbers sometime back.

Correction, decrease of 33dB in the room above.
The link is here.

Last edited by chesseroo; 04/13/07 03:02 AM.
"Those who preach the myths of audio are ignorant of truth."