Basement Theater Design Help (Denver) (1 Viewer)

[EdAngell]

I need some help. We moved into our new home in Castle Rock, CO last July and are looking to finish our basement this spring. My wife has graciously allocated me a small space in the basement that I can build a dedicated home theater. In our previous home of 10 years I had a projector and screen with built-in wall speakers (5.1 system) in our open family room in the pre-finished basement but have always wanted the true, dedicated home theater experience with a room with no windows, theater-style seating, etc and this house was purchased with this dream in mind.

The drawing below shows the general layout of the basement as we are planning it. The dimensions in the home theater box are the open, unfinished dimensions. Realistically, the width would either have to be less than 15' to allow for a walkway over to that sprinkler pipe that is mounted to the wall in the little "bump-out" section, or we'd have to allow for a door on that wall of the theater to have access (unless someone else has a more clever idea?). regardless, the width cannot exceed 15' because that is where support columns reside underneath a steel beam and it is the natural location for the wall. Length of the room can be 20-22' but again depending on need to have "walk around" access. Equipment can be outside the theater room under the stairs as there is a nice space there for a full rack. The basement is completely unfinished and as such there is currently 8'11" ceiling height before we close anything in.

The thick black lines in the picture represent the cinder block walls of the foundation. I would need this room to be as soundproof as possible so that I can be in there watching a movie at full sound level while my wife and her friends are in the craft area and neither one of us can hear the other. Additionally, it would be isolated from the floor above. Directly above this area is the guest room which won't be heavily-occupied, but if my wife's aging mother ever need to join us for an extended stay we wouldn't want it to be an issue. I assume double-studded walls with insulation for the interior walls but single studs/drywall on the exterior walls?

So basically I am still in the planning stage but need some serious help. With the budget in mind, I would like to build out the infrastructure of the room (all wiring, lighting, drywall, carpeting, etc) as phase 1 during the rest of the basement finishing but probably do all the actual electronics/components (screen, seating, etc) as phase 2 soon thereafter. My wife and I are probably going to GC this project ourselves and sub out the work of framing, drywall, electrical to stretch the budget as far as we can.

What I really need is the help with the design so that I can make this happen intelligently. Ideally, I'd LOVE to have someone local who knows this stuff and wanted to help to be involved, but not sure if any of you are "around." Short of that I'd appreciate thoughts on getting started. What other information would be needed for this community to start the discussion?

Thanks in advance.

Ed

 

[Bobofbone]

A more clever idea: the unexcavated area. It's larger, and you can make the height whatever you want. You could pack down the bottom, put real rock on the walls, and have a true "man cave". However, I think the wife approval factor wouldn't be too high with this approach, and anything over the area might have problems with sound isolation. Bugs could also be a problem. So, I'd probably be better off making suggestions you could use.

Regarding the the plumbing; it would seem that putting an access door or panel to the area would be necessary. There are hinges you can find at Lowes or Home Depot that allow a door, or panel to swing out and fit flush. I you incorporate molding on the walls you could make it part of the decor. The other possibility is mounted art, like a poster or picture on the wall.

I assume the red lines are not yet in place. If the two existing walls are cement or cement block, it would help if any framing you put in place had sound isolation brackets for the top connection with the ceiling, and any framing along the outer walls was slightly separated from the outer wall to minimize sound transmission. any duct work running in the ceiling also has the potential to transmit sound through the HVAC system into and out of the theater. If there is any there, it should use some sort of dampening, like insulated flex duct to reduce sound transmission. It would be even better to curve it in a serpentine fashion to break up sound transmission through the duct.

There are a number of wall materials that attenuate sound transmission. I used sound isolation clips, to hold hat channel that kept the dry wall from being in direst contact with the studding, and used double dry wall, with a visoelasic gel (Green Glue) between the layers. All the outlets were lined to reduce sound transmission, and I used fiberglass insulation in the walls and ceiling to further diffuse transmitted sound. The cement floor was covered with a thick vinyl layer, with a wood floor on top, and a Persian (now days, Iranian) carpet over most of the floor. I used a solid exterior grade door for the entry, and weatherstripped the edges, and placed a sound sealing strip on the bottom.

You also need ventilation in the room, particularly if it will be closed with a lot of people in it at times. If the HVAC is run into the area, you will need to deaden sound through the system. You can do that as I described above, or with a muffling system placed in the line. Some of the posts her talk about the latter. I used a different approach. I had an intake and exhaust vent built in, using an inline blower with a variable control, in an enclosed area blowing through sections of insulated flex duct, placed with S curves, surrounded by fiberglass insulation.

How well does this approach work? Fairly well. When I first used my theater, I put the intro to "Top Gun" on, where the F14's are catapulting from the Enterprise, with all the music and afterburners. With the doors closed in the theater, going to the basement and in the bedroom above where my wife was reading, she said the sound was about at the level of a train going by on the tracks about 2-3 miles from our house. The bedroom ceiling fan in medium speed covered the sound from the theater and made it inaudible. Sound that has lots of bass still comes through though. It can sometimes be felt standing on the wood floor in the the area over the theater. I'm using dual subs, that peak at about 1200-1400 watts each. If I leave them off, the lower end vibration from the floor standing speakers doesn't do that.

Make sure your basement doesn't leak before you start. I'd also make sure you don't have any leaks or condensation around the plumbing that will be enclosed.

Most of the construction techniques I described are covered in some of the posts on the stickie posts at the top of the forum. I also had pictures and descriptions on my posts a couple of years ago, under the title Southern Q n' Vu.

 

[DaveF]

Ed, you've got a nice space there. And starting with it unfinished gives you opportunity to makes lots of smart decisions.

Some questions:
* How much seating?
* How many rows?
* Is there a bar / food area involved?
* How important are the aesthetics / do you want it to look like a "theater" with all the speakers hidden?

Here's my initial thoughts:
Plan for 7.1.4 surround sound with in-wall speakers; the front speakers behind an acoustically transparent screen. Depending on your tastes and budget, you can build a the speaker wall forward to install full-size, floor standing speakers and subwoofers behind the screen. You'll lose some depth in the room, possibly eliminating some seating.

Put the screen on the short, exterior was (bottom left in the diagram). Put the door in the long wall at the screen size, so you enter in the front and walk back to seating.

Put the electronics in a closet outside the theater in that top, long wall. Control them via IR blasters. Do two rows of 3-4 seats, back row on a riser.

If your budget is under $50k, buy a 1080p projector and upgrade to 4k in two or three years.

The thick black lines in the picture represent the cinder block walls of the foundation. I would need this room to be as soundproof as possible so that I can be in there watching a movie at full sound level while my wife and her friends are in the craft area and neither one of us can hear the other. Additionally, it would be isolated from the floor above. Directly above this area is the guest room which won't be heavily-occupied, but if my wife's aging mother ever need to join us for an extended stay we wouldn't want it to be an issue. I assume double-studded walls with insulation for the interior walls but single studs/drywall on the exterior walls?

Before with the "as much as possible" attitude, because soundproofing can get involved. I've been researching it the past week; I can't afford full soundproofing, and have been looking into practical sound mitigation options. I estimate the basic materials for soundproofing will be $3500 - $5000 for the drywall, Green Glue, clips and hat channel, and insulation. There's leaves out framing lumber, miscellaneous putty for wrapping all outlets, backer boxes for any ceiling lights and ceiling speakers, and managing the HVAC ductwork, etc. Fortunately, that cost includes what you're spending regardless to frame and finish the walls and ceilings.

This website is a good resource. And if you PM me, I can point you to some other info (that you might already know about).
http://www.soundproofingcompany.com