Starting with a blank slate (1 Viewer)

Hello, I’m new here and building a home theater. Replacing a 27”JVC CRT with a 9’wide screen & projector

I’ve gutted my family room, & patio & merged them, levelling out the floors.

The room is 12’ x 36’ has four large windows & a fireplace.

It is also a hobby / woodworking room.

I’m not worried aboot sound going out, yust trying to keep the sound (kids with 4-wheeled boom boxes) out.


I’ve started with Roxul w/sound barrier insulation in the walls and am going to put the thicker stuff throughout the ceiling which is also open.


My research is leading me towards:

A 2 lb mass loaded vinyl barrier between the studs & the drywall (ceiling & wall)

Soundbreak XP 5/8” drywall for the walls & ceiling

Fire stop putty pads around the electrical boxs

Green glue sealant around all gaps (plugs, windows, etc.)

I will place more insulation atop the screen case as well as the projector case when they finally gets installed.

Possibly acoustical paint under the final paint.


Am I doing too much or not enough?


skål

You’re on the right track. Insulation is beneficial and should certainly be used, but it’s is not nearly as effective as proper room construction that maximizes mass and isolation.


Standard construction for isolation purposes (think recording studios) is room-in-a-room, where you essentially have two free-standing walls (i.e. not sharing a header or footer) right next to each other, and a fully floating ceiling below the existing one.


An alternate solution, not quite as effective, is staggered-stud construction, where the header and footer plates are 2” x 6” instead of the usual 2” x 4”. This allows the sheetrock for each side of the wall to be decoupled as they do not share the same upright stud. You can search “staggered stud wall construction” for pictures to get a better idea.


For mass, double or even triple layers of 5/8” sheetrock for all walls and ceilings.


I visited a fellow enthusiast once who had converted his attached garage to a home theater and had built it staggered-stud with double sheetrock, and in the house you could just barely hear the bass from the sub. So it’s a pretty effective approach.


Also in keeping with isolation and mass is that the room must be air tight. You’d be surprised how much sound gets through air gaps. To that end you want the door to the room to be solid-core (e.g. an exterior door), and fully weather stripped for an air tight seal, as you would have with an exterior door.


Unfortunately, this will cause problems with the A/C system, because they typically rely on gaps around the frame of a door, as well as space underneath the door, for return air. As such with the room air tight you will have to add ductwork for return air.


I’m not convinced that Green Glue is better than any other sealant. Again, the main concern is air tight, and any sealant can do that. Also, I don't see how acoustical paint contributes to either isolation or mass.


Regards,

Wayne A. Pflughaupt

Green glue is like Dynil.

Everything else(of the same type thing) works just as well.

And...

There is "no such thing" as too much soundproofing.

I'm currently rebuilding a house that is less than 1100sf(that counts the converted attic).

The well pump, water softener, water heater, furnace and w/d are all being built into the back center of the house. An entire "new room" is being built.

My plan is...the bedroom on the same wall...you hear nothing come from this room...unless the door is open.

Triple 5/8 acoustic rock (Quiet Rock 500) on 1x2 staggered studs, filled in with vinyl matting. Floor will have two layers of vinyl sound retarding(the floor is the most overlooked. Do not ignore the floor) with the ceiling also 3 layers of QR500, just not with staggered studs.

More research based off of advice here & elsewhere online (& taking into account availability concerns), I’m probably going with:


1 or 2 lb MLV from Trademark Soundproofing ($200 & $300 for 100sqft) & free shipping

Quietrock500 fr the local Lowes ($50 a sheet)

The firestop putty pads, not as expensive as I thought

Dynamat tape to seal the MLV sheets to each other

OSI SC-175 for the caulking needs


I’m still looking for a good acoustic carpet underlayment, but this is not an immediate concern. Should this be used instead of or in addition to, carpet pads?

Thanks for the advice so far, it’s going to cost me more than planned, but, oh well.


skål