Man Cave 90% done, but how do I attach things to wall w/o ruining sound barrier?

[bluewater]

I have a new soundproofed room that has 3 layers of drywall with green glue. It's paint ready. All electrical is surface mounted.
I want to attach things to the drywall, like shelves, picture frames and baffling, but I do not want to ruin the effectivess of the barrier that the 3 sealed layers of drywall are giving me.
I was told that if I start screwing things directly into the drywall, that I would be reducing the effectivess of the sound barrier.
I don't want to make swiss cheese out of my expensive new walls, but surely there is something I can do..maybe a limited amount of penetrations that attach to a wood plank onto which I can attach the things I want. I hope I don't have to have everything free standing.
Tx in advance for the ideas!
Jon

[Randy S]

Well here's how to look at it... Every time you drive a screw or a nail into your wall you are putting a tuning fork into the system. So if you attach a shelf to the wall, than you have not only put the direct connection into to play but ALL the surface area of what ever you decide to mount. There lies the problem...the more surface area tuned into the framing, the more transmission out of the room. A couple screws are not going to ruin the walls as much as what is attached to them...ex. cabinets would be the worst to hard mount, because the cabinet would act like a speaker box.

[Randy S]

Try to free stand as much as possible or glue, if you must attach, maybe use a couple isolation clips and a piece of hat channel attached to the wall, then attach to the channel...at least it breaks the direct connection from vibrating surface to framing. Or something along the same concept.

Picture frames can be hung with screws just dont penetrate all 3 layers if possible.
if you remove screws you MUST fill the holes..
Having the wall system you have (dampening), there is more freedom as opposed to an MLV barrier system.

[whatismisophonia]

I wonder about suspending large shelving from the ceiling close to the wall, letting it touch the wall, and parhaps even screwed with small screws to keep it from swinging or moving.  The suspention cables could be wraped with vibration damping materials and covered by woodwork that touches the ceiling.

[Randy S]

No, the minute you allow it to touch the wall you have turned the shelving into an amplifier for vibration into the wall. speed of sound through wood = 13,000 fps. your putting tuning forks back into the wall.

[whatismisophonia]

i guess im confused; are you talking about the cables i mentioned being screwed into the ceiling joists, or are you thinking i would be putting screws all the way through the wall into the studs?  Im just talking about the joist supporting the weight (dampened cables) and other screws being applied through the shelving a short ways into just the sheetrock on the wall, in order to keep the thing from swinging.  Are you saying the shelving would still vibrate, even with vibration damping material wraped around the cables supporting it, and being in contact with the inner wall would make the wall resonate with the vibration of the shelving then?

[Randy S]

if the cables are decoupled and the wall is decoupled then it would be ok, if the cable is just dampened and the wall is hard mounted then YES you could pass vibration through the system especially if it is low frequency.

Every screw is a tuning fork and wood has a wonderful ability to transmit vibration very very quickly.