This may seem like a dumb question but has anyone used sound board with greenglue then 5/8 drywall? So instead of sandwiching the greenglue between two layers of rock, one side sound board one side drywall? also where can I buy RSIC clips? thanks!!

No but i used Soundboard with 3/4 drywall and the soundboard was a waist of money.

when we remodeled our master bedroom we use 1/2 DW, GG, & 3/4 DW and it works great.

Skip the soundboard, it dose not do a thing for Bass.

I don't think GG can work it's magic unless it is constrained by two stiff layers. Sound board is not stiff.

I predict that Ted will respond with the final answer next time he visits the forum.

Forget the sound board and sound board with Green Glue. You can get the clips and green glue from Ted (www.soundproofingcompany.com)