My Theater will be built in the basement below the great room and the flooring in the great room is this.http://i556.photobucket.com/albums/ss4/sdiaz911/Basement/023-1.jpg


Thinking about placing the following on the subflooring between the I-Joists: green glue then 1/2" drywall green glue then 5/8" drywall. Again this will only be on the subflooring between the I-Joists.
http://i556.photobucket.com/albums/ss4/sdiaz911/Basement/021-1.jpg

Then I will install R-38 (already purchased) in cells between I-Joists.

Then attach whisper clips and 20 gauge hat channel; followed by triple drywall and green glue.

I have children in the house and currently in the unfinished basement any noise downstairs sounds like a bass drum upstairs.

Does this seem like overkill to you?

I got the idea from the following link:
http://www.soundproofingcompany.com/index.php?/solutions/neighbor_noise/neighbor_noise_ceilings


Please chime in

We consult with a few people a day who use this floor/ceiling assembly to combat neighbor noise from above. If you can arrest the vibration before a great deal of it enters the original framing, the rest of your system has a reduced workload.

Questionable in your case since you already have a lot of damped mass and decoupling. If you're really concerned about hearing a footstep pounding during a really quiet scene, then it might be worth it to you. Now is certainly the time for this if you're going to pull the trigger.

Most don't do this, however.

Side notes:

-You could use R19 fiberglass and be as happy

-You should be using 25 gauge Drywall Furring Channel. For those out there wondering, Gunny will be installing clips and channel, but the rows will be separated 16", not 24" to accomodate the third sheet of drywall.

Ted,

Should I use the Mass Load Vinyl or the Pipe and Duct Wrap? Around the pipes in the I-Joists

You don't need anything on the pipes. The decoupled drywall is shielding it