Greedo's Cantina

Have you shown your wife any pictures of the theater seats in a love seat configuration? That might be a good compromise. With regard to the door, do you have any kids in the house? Do you intend to watch movies when there are other people in other parts of the house or when your wife is trying to sleep? What about watching a movie while the clothes are in the washer or the dishes are being run? Nothing ruins a good sob story like the clothes washer kicking on the agitate cycle just as the sparkly vampire professes his undying love and you miss it (miss might be the wrong word there), how about you can't hear it. There are a lot of good arguments to be made for soundproofing, and only a few against. Perhaps a nice wide door that can be left open except when you want the sound isolation. Lots of trim to dress up the casing to add to the visual appeal. Again, I'd look for a compromise that you both can live with there.

How many seats do you want in your room? How far does the beam drop below your 7'-8" ceiling? I'm interested to hear more about your plan. My first thought is you are giving up a lot of space behind your false wall. If it's not too low, you might move your screen further back or consider flipping the room 180 and put the screen on the other wall. That may nor may not work depending on the depth of the beam.

And finally, have you started considering HVAC? That's generally one of the biggest concerns early in a design.

Is that 11" below the the other joists? So floor to ceiling under the beams is 6'-9"? What type flooring are you planning that will require 3"?

If you are thinking one row of four, depending on the seats you pick, it might be tight along that 14' dimension. Looks like fusion lagoons' in a love seat configuration in the middle come in at 118". That will only leave around 51-52" for aisles. Off hand, I can't remember what the recommended minimum aisle width is. If you are going for two rows of two, then there's a whole other set of problems with your ceiling height. I wonder if putting the screen on the long wall and having a single row of seats would work well in this setup. Just thinking out loud at this point. Thinking outside the box and all that.

With regard to the sound isolation, I was just trying to give you some ammunition for your debate with SWMBO. Soundproofing works in both directions, while it's great to keep sound in so you can watch a movie without waking the kids, it's also beneficial in keeping sounds out so that you don't have to turn the volume up and down between quiet and loud scenes. Also, you may be aware of this already, but bass traps are for smoothing the in-room bass response, not for keeping the bass in the room.

For HVAC, unless you get extremely lucky, and the HVAC guys is a HT enthusiast, he will likely underestimate the HVAC requirements for a dedicated space. It's been suggested on these boards in the past to size the theater like a kitchen for heat loading, and you also need to keep the velocities below 250 fpm.

I assumed you were planning to plug and cover the window. It may compromise your soundproofing otherwise, although it's mentioned before that windows are bass traps

I'm subscribed. Interested to see how things develop.

Greedo,

What are the dimensions of the room? I might have missed them.

So you were planning to have the rear wall be along the beam? Is there any way to eat into the next room to make the room larger?

Like JPA said: The beam in the front being 11'' from the ceiling is significant. Mine is 9.75'' and it is wreaking havoc. I am doing 2 rows so if you only do one row there won't be an issue with the second row viewing angles. Flipping the room could solve this problem though. You won't care about the "cave" effect when the lights are off.

If you can convince your wife to put in a door it would be huge. I am just like you in that I want to do most of my movie watching after the kids go to bed. And I like it loud. Be prepared for constant frustration with the volume control if you do not have a door or soundproofing. And I think it is true what you said about the low frequencies and the difficulty keeping them contained. However, I find that if a moderate low rumble goes through the house it does not wake up my 18 month old boys if they have a fan on in the room. I would try to soundproof if it is within your budget to keep a low noise floor in the room as well. You can definitely take care of the high frequencies. I found Ted White (and John) at thesoundproofingcompany to be very helpful. I decided not to soundproof at first because of budget but I slowly came around. After hearing the results for myself in a soundproofed theater at the Omaha theater tour lately I am glad I did. If it is not in the budget then just be happy with what you have.

If you do not have any walls down there you can build them so they do not touch the foundation walls, then clip and channel the ceiling and you will be miles ahead.

Love the name of your theater!

+1. Without a door, I would probably get a nice pair of headphones, and wire appropriately. Don't read that as me being a d-bag, I'm serious. That's the only way I watch movies after bedtime now. I got tired of the volume shuffle. It's not ideal, but it's better than nothing. I can't wait to get my theater done, lthough, and I'm going to be very disappointed if the soundproofing isn't good enough to let me watch a movie with the kids in bed.

Before I gave up, I'd certainly try to find a creative door approach that would please the wife.

It really sounds like step one is to decide if you guys want a dedicated space, or a more general purpose entertainment room. Of course, there's nothing to say you can't have a window in a dedicated space, but it does raise some issues with sound containment and light control. You will also need to keep in mind where you will put your side surround if you cut that stairway wall back considerably.

Using IB3 clips to attach the top plate will decouple the top. You can also put the drywall on clips and channel. On the wall. build a beefy air tight removable window plug that attaches to the decoupled wall. Just another note, staggered studs serve no purpose on exterior perimeter walls.

With sound proofing, as with all things in life, bigger is better. Having the thicker sheets of drywall would be better. Someone else might chime in here - but would three layers of 1/4" be possible? Still thinner than two 5/8", but with the additional layer of greenglue means additional soundproofing.

I'm not sure how three layers of 1/4" with GG between each layer would compare to two layers of 5/8" with GG as I have never seen lab data directly comparing those, but my gut tells me that you'd be losing something with the drastically reduced mass you'd get from the 1/4" assembly. Not to mention that it would be much more expensive to do it that way.

Regardless, the difference between one layer of 5/8" and two layers of 5/8" is 1.25" along the length of the room. I understand conserving space, but that is hardly significant.

1/4" drywall sandwiches will flop around. Double 5/8" would be better.

I'd rather see you use two sheets of 5/8" and 1 layer of damping, rather than three sheets of DW and 2 layers of damping. Save your cash...

Soffits are not the best to absorb low frequencies. I wouldn't even consider that a factor in the grand scheme of things.

Don't worry too much about it? Wow.

Mineral fiber and fiberglass batts are both approved for use as fireblocking. Just tightly fit the area between the wall-ceiling connection with either and you're compliant.

If you decouple the GWB from the beam with clips and do the two layers of drywall with GG I think you'll be fine. Many of us have areas like that.

Tim

Sorry, Gypsum Wall Board.

Tim

You can either block out between the flanges with wood or secure wood to the bottom flange (but you lose head height with that method).

Assuming you pack out between the flanges, you would attach the clips to the wood blocks, then use a 20ga angle ("L") or a block of wood (ie a 2x2) to create the bottom corner. The drywall below the beam would attach to that, not the beam.

A good ramset will secure wood to the beam (ie a Hilti, do NOT try with some cheap Home Depot gun), or you can use TEk screws, or you could just glue 2x with PL, use a clamp to secure both sides at the same time. Remember, you only need a block every 2'.. you don't need a continuous piece of wood the entire length.

Tim

Am I reading this correctly that fiberglass batts in the wall cavities is sufficient for fire blocking?