Atmos!

April 4th, 2016

atmosAtmos is finally in our house!

 
 

Seven identical speakers around the room, two independent subwoofers, and four identical overhead speakers for a 7.2.4 setup. Mary’s response upon hearing a Dolby Atmos demo trailer— “Oh wow!”

Then we watched Mad Max: Fury Road in 3D and Atmos, which I had been saving as the inaugural film.

Subwoofers

March 2nd, 2016

Because my theater is small, I’ve got to be creative in hiding all the gear. The electronics are all outside the room, but that doesn’t work for speakers. For the seven surround speakers, I’m using identical MTM in-wall speakers that will all be hidden by either the screen, or fabric panels that will cover the walls. For the four overhead Atmos speakers, I’m using four identical in-ceiling speakers that’ll also be covered by fabric. You won’t see any of them. However, it’s a little more difficult when it comes to subwoofers.

Like my last house, I could’ve put a store-bought subwoofer in a front corner of the room and been happy with the sound. But I didn’t want a typical black box that stood out in an otherwise clean room. I also wanted bass that was loud, low and clean—which isn’t cheap when it comes to subwoofers. And I’m cheap thrifty.

 

Many people who build dedicated home theater rooms in their houses who have larger rooms, are able to build false walls for their screens, and are able to hide large ported subwoofers behind these walls, keeping the decor of the room clean. As my space is only 12′ 2″ x 16′ 6″, I don’t have that luxury.

So I decided to build my own subwoofers that I can build into my front stage. Parts Express had 15″ Community subwoofer drivers on sale, which would be perfect for a pair of sealed subwoofers in my room. These drivers are normally used for pro-audio subwoofers that cost well above what I’m willing to spend, but because I’m building these myself, I’ll be enjoying quite a cost savings.

The math said that with these drivers, a box size between five and seven cubic feet of volume would give me the best performance. So I designed a box two feet high, one and a half feet deep, three feet wide in the back, and two feet wide in the front. Taking into account insetting the back and front, driver volume, and bracing volume, final interior box volume is just under six cubic feet.

 

While I previously build a bass amp out of baltic birch plywood, for this project I decided on using MDF due to its higer density and weight. It also mills and cuts very easily. Unfortunately, It does not hold screws or nails well. Because of this, I decided to assemble the boxes with traditional joinery via dados and rabbets with wood cleats to hold screws. Adding glue, caulk, and bracing, these will be very strong boxes. I filled them with five pounds of poly-fill each.

The math also says that with taking room gain into account, I’ll be able to hit 110db from 23hz to 120hz ±3db at the front row. We’ll find out how well practice hits theory later.

To fit the design of the room, the tops of the subwoofers will be covered in the same bamboo flooring that I used in the rest of this project, and the front and angled side will be covered in the same navy fabric that’ll cover the walls. The stage piece between them will also be finished the same, after being stuffed with insulation to keep from becoming a resonant cavity.

 

Once assembled, I tested by powering ’em with an old Pioneer VSX-D850S whose preamp stage had been fried by lightning. I wasn’t sure if the amp section would work at all, and I also wasn’t sure if the rated 110 watts to each sub would be powerful enough, but to my happiness, it did, and it is. And holy moly do these subs deliver. I still need to buy a measurement microphone to see if I’ve hit my mathematical goals, but in several weeks of music and movies so far, my ears (and body) say success.

 

Theater Entrance

November 19th, 2015

Theater Framing StartedIn our last house, we didn’t have a dedicated theater—it was a media room that included a bar. It wasn’t that I didn’t want a dedicated theater, but I didn’t have the room to build what I really wanted. In the end, it worked well, and we enjoyed the room.

In the new house, I’ve got room to put in the dedicated theater I really wanted. Sure, I don’t have the size or scale to do a Theo Kalomirakis theater, but I can still do a room with tiered seating and matching, hidden speakers mounted at the optimal placement around the room, instead of having the surround speakers hanging from the ceiling.

Doors FramingBecause it’s a dedicated room, I wanted an entrance that would show that what lies beyond was not just a bedroom. And because the most logical place to put the entrance was on the riser, I decided on a curved stair in front of the doors.

 

 

 

Doors and RiserOf course you can’t exactly go into Home Depot and buy a curved stair kit. Or if you could, I’ve never seen one. I didn’t want it sticking out too far in the room, otherwise I thought it could become a tripping hazard while shooting pool. After a number of drawings, I settled on a curve with a radius of 24″.

 

 

stair01The bullnose stair trim has an inner radius of 22″, and outer radius of 25″. I rigged up a template from ¼” plywood and trimmed some leftover walnut from the bar using my shaper.

 

 

 

 

stair02I used the inner 22″ radius to mark the correct curve for the bamboo flooring on the stair. Once Mary poly’d the walnut, it took on a similar tone to the bamboo.

Flooring

October 13th, 2015

floor01I‘ve got 800 square feet of ½” bamboo flooring to install. Mary has been a bit impatient with it, as it took two weeks from the time we ordered it until it was delivered, then another two weeks for it to sit in the house, acclimating. The place from where we bought it delivered it to the garage; Mary carried most of it to the ground floor* one box at a time as this stuff is heavy. Seriously—800 square feet was over 1,000 kilos.

 

floor02The bamboo is being laid in the tavern room, the billiard room, and on the riser in the theater. I’ll also have enough left over (I hope) for the future bathroom. On the main level in the theater, I’m framing the room with three courses of the bamboo, with carpeting in the center.

 

 

 

floor04After getting the bamboo up to the bar, I took a vacation day to get the rest knocked out in the tavern and billiard room. It took the entire day to get that last bit done, and another full day to get the riser done in the theater, which included milling custom bullnose trim.

 

floor03
 

 

 

 

 

 

 

* We’ve decided to call this floor our ground floor instead of a basement, as the floor is two feet above grade in the back of the house, is flooded with natural light, and has a ceiling height that is taller than the top floor of our house, with the exception of our master bedroom. Pretentious? Maybe.