[Pez]

YO!!!! AC people, been out of the game for a few months. We moved to a wonderful new house with an unfinished basement. I have a permit for my new audio room I'm going to start very soon in the basement. My room dimensions are: 23'X15'X8' Brian Pape helped me pick the dimensions. I'm going to have a separate equipment room for both video stuff for future expansion and house my server for music and video for my entire house.  A few things, I have to have a drop to 7' on the ceiling through the middle of the room for the I-beam and the vent/return for the upper level. I have thought about maybe re-routing the vent/returns, but am not sure if this can be accomplished realistically.

Any way, I was hoping to get some feedback as to how to reduce sound pollution from the upper level and of course into the audio room. Isolation ideas are welcome. It may be hard with that vent there and the fact that the audio room is literally right below the living room. Also any other suggestions for construction, materials etc would be greatly appreciated.

[bpape]

Lots can be done to reduce sound transmission into and out of the room.  Primarily, it's 3 things - mechanical isolation, mass, and damping any cavities.  HVAC can be isolated relatively easily by adding mass. Also, you should consider changing the ducting to flex or duct board if it's tin so it doesn't resonate and transmit sound as easily.

If you want to give me a call, it's a pretty deep subject.  Probably easier to talk on the phone.

Bryan

[Pez]

Again, Bryan to the rescue! I'll give you a call later on today. 

[mgalusha]

I know a good contractor, he had no problems with the double drywall, rubber mounted ceiling and green glue in my room. Not the cheapest but not the most expensive either. Shoot me an email if you want his info.

[Pez]

This ones going to be DIY Mike. Do tell me more about rubber mounting and green glue. These are new terms to me.

[mgalusha]

This ones going to be DIY Mike. Do tell me more about rubber mounting and green glue. These are new terms to me.

Bryan will fill you in on that. Basically the ceiling drywall is hung from rails that are mounted with rubber isolated hangers. There are two layers of drywall with several tubes of green glue between them. This is a non drying, visco-elastic compound that reduces noise transmission and ringing of the drywall. The rubber isolation also reduces noise transmission.

Just be sure to keep in mind that Colorado building code requires floating walls, which means that your listening room walls will be attached to the floor above, no ideal but not optional either.

[jtwrace]

Just be sure to keep in mind that Colorado building code requires floating walls, which means that your listening room walls will be attached to the floor above, no ideal but not optional either.

How do the walls attach to the concrete foundation then?

[bpape]

It's kind of odd.  They really don't. There are metal studs that come up through the floor so the wall can float vertically when the ground heaves or shifts.  You can put a nut on a threaded rod but if it heaves or drops, basically it would pull the bottom plate off the studs if I remember correctly.

Bryan

[Pez]

Actually you bolt a 2x4 directly into the ground. Then the wall is attached to the ceiling only. The wall is then fastened to the 2x4 in the ground with a giant nail which allows it to float up and down without buckling. The problem is even though this allows the ground to heave you'll find that your doors may no longer open and close appropriately like in my father in laws basement. 

[PDR]

Thats a little different.....in commercial buildings the top steel track is usually embedded into a steel slip track....its a little wider and deeper than the receiver track that the steel studs seat to, this allows the the roof to move up and down with the snow load. You could reverse it and hand from the truss and seat to the slip track below if you have heaving problems.
Not sure I understand why the floor would heave to begin with though.

There are products available thru drywall supply houses that look and hang like a T-bar ceiling that you can attach drywall too. Unless you have experience with constructing steel or wood suspended ceilings this would be the easiest to build.....it just clicks together. I would suspend the main tees between your floor joists and let the isolation clips.....you can DIY these, or purchase...hang from between the joist from horizontal supports attached to each side. This would be easy and the result would be only a 1-1/4" loss in height. You can then put 2 layers of drywall with whatever kind of acoustic caulking you like between the two.

I'm not sure why code would say you have to attached the top of the track to the floor above, you could attach the walls horizontally to the existing structure with a piece of rubber between the clips....no?
Leave a 1\4" gap between the ceiling and walls, then caulk instead of plaster and you have pretty well decoupled the room from the sides and top.

Have been an Interior Systems Mechanic for 32 yrs...have built many sound proof rooms.....even interrogation rooms for police with 600lb cam hinged doors and frames...radio and TV station isolation booths/rooms for announcers and bands. No expert but can let you know how we built them for the acoustic engineers, if it helps any.
 

[JLM]

Lessons learned from my dedicated room:

+ insulated fiberglass exterior door with weather seals
+ lined fiberglass ductwork
+ insulated staggered stud walls

++ having an acoustically isolated room (listening flexibility with lock on door)

- recessed can light fixtures (even with 1 ft of fiberglass on top sound transmits)
- single sheet of drywall screwed directly to ceiling (builder wouldn't cooperate)

[Pez]

Was going to do can lighting.  Any better solution other than lamps everywhere?

[JohnR]

Any better solution other than lamps everywhere?

More tubes?

 

[JLM]

LED lights are really coming on (extremely energy efficient, extremely long life, available in any color, more option everyday, prices coming down as with any new technology). 

In the next year or so I might replace cans with wall sconces and add green glue/second drywall layer to ceiling. 

Indirect lighting is another rather pleasant option (with whatever bulbs).

[bpape]

Can lighting is a lot of holes. 2 options.

1.  Build soffits in the room after the drywall is in so you can recess them in the soffits without penetrating the shell.

2.  Build MDF backer boxes to enclose the cans.

Bryan

[SlushPuppy]

Lessons learned from my dedicated room:

+ insulated fiberglass exterior door with weather seals
+ lined fiberglass ductwork
+ insulated staggered stud walls

One of the most important items on the list. I have a dedicated listening room and was surprised how much sound was getting into the rest of the house UNTIL I realized my builder used a standard interior door. The sound outside of the room went down dramatically after we swapped it out.

[Nyal Mellor]

Speak to one of the sound isolation companies like http://www.soundisolationcompany.com/. Very helpful and have quite a few regional places where you might be able to pick stuff up to save on shipping.