Sealing gaps for maximum isolation?

I'm building a listening room/tech lab for a high-end consumer audio system designer/installer. Sound isolation is reasonably important, both to keep the music inside from bothering folks outside, and to keep mechanical, environmental, & other noises outside from disturbing the listeners inside. Didn't go too exotic on the wall construction (mostly due to an accelerated construction schedule & an over-zealous contractor). Inside leaf is 3/4" plywood plus 2 layers of 5/8" gypsum board. And it's already installed, being taped/mudded this week. Outer leaf will be 2 layers of 5/8" gypsum board, but that's not going up until all the wiring is in place. Since this is a tech lab, there are TONS of low voltage audio & video wires running all over the room, from a master patchbay to a dozen or more subpanels scattered around the room. Naturally, each one of those patchpanels corresponds to a big hole in my 3-layer inner leaf! So before the outer leaf goes up, I want to seal all of those patchpanels with whatever will provide the most thorough airtight acoustic seal possible. Got any suggestions? I was thinking (in no particular order) - acoustic caulk? - spray-on expanding foam? - QuietPutty? - tiny sheetrock subenclosures? Solutions greatly appreciated!

nevermind, I found the thread about PuttyPads