how do I finish these wall/door details

[Godskid]

Thanks everybody for the great resource.
I am about to begin construction on a remodeled control room and have a question about how to finish the GAPS between my non-connect walls with the minimum sound translation between these walls. I have attached a drawing of how things are arranged. It is a side view representing a doorlock. Presently there would be open space between the walls that would be visable and would become a open resonant chamber unless properly sealed. How Do I Seal This? I was thinking high density grey upolstery foam wedged in the opennings then putting some kind of patterned Auralex foam for looks, but this seems lacking as there would still be excessive bleed through the foam, yes?--- I just don't know-- any advice would be awesome. God Bless, David.

[knightfly]

Please check your other thread for some ideas... Steve