Quick question...

What spacing should I use for the studs in the ceiling? I framed the 2x4s 24" OC but I fear that is too far apart and it is not too late to change it. Should I go 16" OC or 12" OC (since I already have the 24" spacing going)?

Please help.

(I am using a single layer of 5/8s" drywall on the ceiling).:confused:

24" OC is standard for non load bearing ceilings..........what is the span?

The 2x4's are perpendicular to the ceiling joists?

If you are using 5/8" drywall you will be fine. Anything thinner and you should use 16" O.C.

room is 10'8"x23'. Should I put the drywall up and frame it parallel to the studs so I have the drywall screwed to the studs on the outside edges and 1 up the center or should I turn the drywall 90 degrees?

If I understand, you are building a floating ceiling independent of the original? If so, the spacing will not affect the soundproofing performance. It's completely decoupled.

So the only consideration boils down to stability. I figure you must have 13' of span at least. Seems like a lot for 2x4s 24" on center.

Yeah take a look at this ceiling joist span table (http://www.mcvicker.com/resguide/page013d.htm)

For 2x4 24OC span should no be greater than 7'. Even on 12OC its still 10". Looks like you should add 2x6 in betwen the current 2x4 to get the support you need.

If you framed a 2x4 ceiling below the existing 1st floor joist to drop below ductwork as I have done just make sure there is at least 1 or 2 2x4s going up to tie into the existing structure. This will eliminate span problems.

That would couple the currently decoupled ceiling, though. Unless a spring isolator was used. Like from Kinetics or Mason.

Just noticed width is 10'8" so will probably be OK with extra 2x4's 12OC, but if you were doing DD would go for the 2x6's......but a few RSIC's may be easier if you can get a few easily.

No coupling here. I do have some braces coming down from the ceiling joists above. Sound proofing isn't much of a concern- I've got plently of R-19 to bring the sound levels down to a comfortable level. I'm single so I dont have to worry about the whole wife factor. The bedrooms are 2 stories up as well.

The center of the room has a raised ceiling that will have the blue rope lighting sitting in crown molding to complete the theater look some of you have showcased perfectly. That takes up the middle third of my room so, I have 2- 10' x10' areas of the ceiling that I am framing up 2' OC. I guess I will take some down and throw in some more studs to get the 16" OC that is apparantly desired.

That will lead to my next problem... It looks like my projector is going to need to be mounted near the center of my 12" raised portion of my ceiling. There has got to be a drop mount that I can purchase to mount my projector where I will need it to be. I am buying a Sony VW60 Black pearl and I am going to use a 104" Carada screen, how far away do you recommend I mount the projector (so I can get an idea as to where to run the HDMI cable)?

Thanks guys.

Just a correction - those span tables were for Douglas Fir. Not sure what your using but here in NoVA it seems to be Southern Pine that looks to have better span strength. Looks like you need to check the grading of the lumber.

http://www.southernpine.com/spantables.shtml

That span table is Southern Yellow Pine (SYP), which I think is mostly sold as pressure treated lumber.

Most "regular" dimensional lumber is now SPF (sprice-pine-fir) in which the P (pine) is not the same trees as the SYP. They are weaker, and the spans are shorter.

Brian is right on the money. SYP has the structural MOE (Modulus of Elasticity) of Red Oak, to give you a reference. SPF is much softer, lighter, and more flexible.

The span on my new theater is 21' the framer used (2) 2x10 DOUBLED together 24OC

The span on my new theater is 21' the framer used (2) 2x10 DOUBLED together 24OC

That would definitely provide the added support one would need. Most of the main part of my house is constructed with sistered 2x12s.