How to build a theater in 1,110,993 easy steps

**steverc** · **09-05-09, 12:10 PM**

Well hey there Darryn:

I've been watching your thread for a couple of weeks and just noticed we're neighbors. I'm just down nine east of Woodinville. Being a Software engineer odds are about even that you drive right past my home on your way to work.
Very nice job on the theater! I love the behind the screen speakers, I don't have enough length to pull that off but I would have if I could have. DIY is so much fun. I also have an IB sub, it's way beyond anything else I've ever heard. Luckily my nearest neighbor is a few hundred feet through the woods so I don't think they can hear anything even when I play it loud. At least they have never complained.

Steve
http://www.kn7f.com/Theater/Finished/

**seattle_ice** · **09-05-09, 01:01 PM**

I just finished running the main braces for my subs. I will add a little cross (X) bracing later, maybe after I insulate this whole room.

First I ran some upright braces between each driver:

Then I ran some 2" x 10"s from the back of the brace to the outside wall along the floor. These are nailed and glued with PL400 heavy duty construction adhesive.

I then drilled a 1/2" hole 24" off the floor in 4 locations on the outside wall. After inserting anchor bolts, I used a coupler to attach some lengths of 1/2" Allthread.

The other end I used some angle pieces I had to fab up some connectors. I lagged those to the LVL beam that holds the wall over the subwoofers and connects to the top of the subwoofer baffle with (2) 3/8" x 2" lag screws each. The other end of the Allthread was then bolted to them and tensioned with a lot of force.

When that step was finished, it looked a little like this:

**seattle_ice** · **09-05-09, 07:58 PM**

Quote:

steverc wrote:

Well hey there Darryn:

I've been watching your thread for a couple of weeks and just noticed we're neighbors. I'm just down nine east of Woodinville. Being a Software engineer odds are about even that you drive right past my home on your way to work.
Very nice job on the theater! I love the behind the screen speakers, I don't have enough length to pull that off but I would have if I could have. DIY is so much fun. I also have an IB sub, it's way beyond anything else I've ever heard. Luckily my nearest neighbor is a few hundred feet through the woods so I don't think they can hear anything even when I play it loud. At least they have never complained.

Steve
http://www.kn7f.com/Theater/Finished/

Hey;

I actually work at home, so I don't drive out much. We did go right by you when we drove home the back way from the Foreigner concert at Marymoor a couple weeks ago. Nice to hear from someone in the neighborhood.

What speakers and subs are you using for your setup?

**steverc** · **09-08-09, 09:26 PM**

Quote:

seattle_ice wrote:

What speakers and subs are you using for your setup?

For the mains and surrounds I use MG IIIa from Magnepan and the sub is four MJ-18s from mach5audio.com in about 900 cubic feet of attic. I drive the subs with my old Denon 2808 receiver.

**rickp** · **09-09-09, 02:19 PM**

Nice install on the IB. May I make a suggestion? Although the all thread is installed perfectly, the top portion of your enclosure is where you will have the most force from the speakers. The all thread will flex and viberate under the load, if you replace the all thread with a 2x6 I think you you will be ahead money and time.

Regard, Rick.

**seattle_ice** · **09-09-09, 02:35 PM**

Quote:

rickp wrote:

Nice install on the IB. May I make a suggestion? Although the all thread is installed perfectly, the top portion of your enclosure is where you will have the most force from the speakers. The all thread will flex and vibrate under the load, if you replace the all thread with a 2x6 I think you you will be ahead money and time.

Regard, Rick.

Interesting you should say something... They might flex some, but will offer much less compression and extension than wood would. I think I would be most worried about vibration. And I cant be ahead in money that is already spent now, can I?

This is actually one step along with my experiments. I am going to try a few different things and check the results. The beam that the allthread and the top of the speaker baffle is attached to is 2-1/2" X 14" x 8' and weighs almost 200 pounds, so it has a fair mount of mass to begin with. Plus the speaker baffle top and bottom are almost 14" deep at the center, so there is some resistance to lateral deflection there also.

The Allthread is currently tensioned with the nuts at 200 ft/lbs. When I get a chance, I will run the stereo with an accelerometer attached to one of the pieces of allthread, then attached to the beam above the subs. Then I will start adding diagonal braces from the middle of the Allthread to the bottom brace, then add other braces and see what happens. Building and testing things is FUN STUFF!

**rickp** · **09-09-09, 03:50 PM**

Most people assume push rods in an engine don't flex because the pushing is done on axis but with the advances in technology we can actually watch a push rod in super slow motion, very interesting they look more like pole vault poles then push rods. A 2x6 has substantially more mass than the rod. The reason I suggested you would be ahead money is by the time you are finished bracing everything you will have spent to much more time and money that is if you are compelled to make every thing PERFECT, as I am. Boy that causes me alot of stress! Anyhow please post the results of your accelerometer test, I was planning on using a load cell to test mine but since we have to move I am finishing it just the way it is.

**seattle_ice** · **09-09-09, 06:26 PM**

Quote:

rickp wrote:

Most people assume push rods in an engine don't flex because the pushing is done on axis but with the advances in technology we can actually watch a push rod in super slow motion, very interesting they look more like pole vault poles then push rods. A 2x6 has substantially more mass than the rod. The reason I suggested you would be ahead money is by the time you are finished bracing everything you will have spent to much more time and money that is if you are compelled to make every thing PERFECT, as I am. Boy that causes me alot of stress! Anyhow please post the results of your accelerometer test, I was planning on using a load cell to test mine but since we have to move I am finishing it just the way it is.

The forces acting on a pushrods are many orders of magnitudes higher than four subfwoofers.Pistons are changing directions 200 or more times per second traveling 600 inches (50 feet) per second when an engine is doing 6000 rpm with a 3" stroke.

I also went and weighed the pieces. When wet, then 2" x 6" weighed almost 5 times the allthread. BUT - a really dry 2" x 6" only weighed slightly more than twice the 1/2" Allthread. That is not a ton more mass.

Now the 2" x 6" would be much more resistant to deflection from a lateral direction and from vibration (like a violin string) than the allthread.

**seattle_ice** · **09-09-09, 10:03 PM**

Ok, I did some quick testing and dont even really need to get serious to see one effect we were discussing. At certain frequencies, the allthread visibly vibrates. Not huge amounts, but enough to see.

I loosened up one piece of Allthread, and cut and temporarily inserted a 4" x 6" alongside the allthread from the beam to the wall, then clamped the nuts back down, effectively squeezing the 4" x 6" very tightly in. This made everything completely damped. No vibrating of the allthread no matter how loud or what music I played. Plus the wall seems extremely solid, as it is pulled very tight against the 4" x 6" by the allthread.

I think I will add 4" x 6"s next to all the Allthread pieces, and clamp the Allthread to the side of each one. That way, everything is squeezed very tight with nowhere to move (at least on the scales that matter)

**SQCherokee** · **09-10-09, 02:59 AM**

looks great so far. Any plans for accoustical treatments in the room to deal with reflections from all the wood work?

**seattle_ice** · **09-10-09, 08:45 PM**

Quote:

SQCherokee wrote:

looks great so far. Any plans for accoustical treatments in the room to deal with reflections from all the wood work?

No definite plans. I figured once the room was carpeted and furnished, I would start taking measurements and using REW and the BFD for my subs, and the Audyssey EQ in my receiver to establish my baseline. Then determine what will be necessary.

**rickp** · **09-12-09, 09:24 PM**

Quote:

I think I will add 4" x 6"s next to all the Allthread pieces, and clamp the Allthread to the side of each one. That way, everything is squeezed very tight with nowhere to move (at least on the scales that matter)

Excellent solution, good thinking.

Looking forward to seeing more progress, keep up the good work!

**seattle_ice** · **09-15-09, 10:19 PM**

Ok, loosened the allthread, put in the 4" x 6"'s next to the allthread with nails and glue, then tightened the crud out of the it. Nothing is moving at all now.

I also got the fans installed in the walls, and I insulated everything. I still haven't decided what to do with the outside of the speaker boxes, but that will have to wait until I am done testing them anyways. The fans are the dark square - they are dark because I put some filter media over them.

To run the fans, I ordered a couple of cheap 12VDC power supplies, then I found a thermostatic outlet bar. It turns on at 78 degrees and then off at 70. So I plugged that into the wall and the two power supplies into it.

Works like a charm. The fans only run when it gets over 78 degrees and then they stay on as long as it takes to bring the temps back down.

**Gregavi** · **09-24-09, 12:29 AM**

Looks good. I'm in the process of converting my 2 car garage into a home theater and came across your thread. I have been reading through this and it has become like an HBO series. I can't wait until you post more. The only criticism I have, other than your over the top attention to detail, is that you spend so much time writing and posting photos. When do you sleep? You must be retired because us working stiffs have a hard time finding time to build something like this, much less, write about it too. Lucky for us.
PS
Does that “1,110,993 easy steps” keep changing like the “McDonalds Served” count?

**seattle_ice** · **09-28-09, 01:37 AM**

Quote:

Gregavi wrote:

Looks good. I'm in the process of converting my 2 car garage into a home theater and came across your thread. I have been reading through this and it has become like an HBO series. I can't wait until you post more. The only criticism I have, other than your over the top attention to detail, is that you spend so much time writing and posting photos. When do you sleep? You must be retired because us working stiffs have a hard time finding time to build something like this, much less, write about it too. Lucky for us.
PS
Does that “1,110,993 easy steps” keep changing like the “McDonalds Served” count?

I wish I was retired. I am cursed with way too many interests. I was blessed with parents that did not believe in the word "NO". We were taught early on to try everything, and not to limit ourselves.

When I was building the house, I was like a zombie for months. Get up at 5 am. Write some software for 90 minutes. Drink super gigantic coffee on my way to jobsite. Work on house for 8-10 hours (12-20 near the end). Come home, try to eat fast enough not to taste it. Take care of home projects (Honey-do's, lawn mowing, etc..). Work on software from 9pm-1 am or so while drinking large quantities of coffee and coke. Rinse and repeat, sometimes 7 days a week.

I write most of these at night, after my wife has gone to sleep. I sleep about 6 hours a night. I work on my software mostly from 7am-2pm and 10pm-1am. So the theater and speakers and cars and furniture and music gets worked on during the middle of the day and weekends.

I also workout with freeweights and an elliptical for an hour every day at 5 pm, 3 days on, 1 off.

**seattle_ice** · **09-28-09, 01:38 AM**

I went down to the Home Depot, and after dodging the 112 guys looking for work like I was Barry Sanders (only much slower, older and fatter and no one was actually trying to tackle me - although one guy did kind of have that look...), I found some great shelving with huge load capacities. It is the track kind, where you mount the track on the walls, then you can install brackets wherever you want, every two inches or so.

The shelving is ~18" deep, and rated at 600 pounds per pair of brackets. I used some large 3" screws to mount the tracks to the studs in the wall, then mounted some shelves. I really wanted to use the wire shelving for airflow through my equipment.

After sliding in some of my equipment, it looked like this:

A day after that picture, my blu-ray player showed up. It doubles (secretly so the wife doesn't hear) as a Playstation3 slim. Just gotta love the media streaming capabilities also. Although I did have a huge debacle trying to purchase the PSP3 from Sears via PayPal. Lets just say they still do not have the kinks worked out of that payment option.

I have the Earthquake Cinenova powering the L/C/R speakers, and the Onkyo 876 powering the surrounds. The Earthquake was measured at ~.006 THD + Noise @ 113 db @ 600 wpc into 4 ohms with all channels driven. ;x(

I made a bunch of interconnects with some nice 12ga wire and the excellent banana plugs from PE with the double set screws. I use some military heat shrink on the joints and they are completely air tight and very strong.

**Gregavi** · **09-28-09, 11:41 AM**

After reading how hectic your life is, I hope you take the time to relax when you are finished and actually enjoy the fruits of your labor.
I have the 5 Channel version of the Earthquake Cinenova. Love it! The best piece of audio equipment I have ever owned.
It looks like you are using speaker wire that is not “in-wall rated” (CL-2 or -3). Any reason for that? I’m considering doing the same thing since I have hundreds of feet of good quality 12 ga. wire. Comments?

**seattle_ice** · **09-28-09, 12:05 PM**

Quote:

Gregavi wrote:

After reading how hectic your life is, I hope you take the time to relax when you are finished and actually enjoy the fruits of your labor.
I have the 5 Channel version of the Earthquake Cinenova. Love it! The best piece of audio equipment I have ever owned.
It looks like you are using speaker wire that is not “in-wall rated” (CL-2 or -3). Any reason for that? I’m considering doing the same thing since I have hundreds of feet of good quality 12 ga. wire. Comments?

I certainly plan on enjoying this when it is done!

There might be some very, very remote outside chance that if you push way too much current through the speaker wires that they migh overheat if they are not in-wall rated.

I am not worried. Pushing 100 watts through 12 gauge wire is like taking a drink from a fire hose. There is no chance the wire will be overloaded and get hot. Now, stranded wire is not exactly the same as solid, but 12 ga. romex is rated to way over 20 amps of current * 110 volts = 2200 watts. You can run 80% of capacity forever and it will not even get warm to the touch.

**Gregavi** · **09-28-09, 09:05 PM**

Quote:

seattle_ice wrote:

There might be some very, very remote outside chance that if you push way too much current through the speaker wires that they migh overheat if they are not in-wall rated.

I am not worried. Pushing 100 watts through 12 gauge wire is like taking a drink from a fire hose. There is no chance the wire will be overloaded and get hot. Now, stranded wire is not exactly the same as solid, but 12 ga. romex is rated to way over 20 amps of current * 110 volts = 2200 watts. You can run 80% of capacity forever and it will not even get warm to the touch.

Actually, I'm not worried at all about potential fire. What I am a tiny bit worried about is, if there ever were a fire, the insurance company could, and probably would, use that against you/me in a claim. It’s something I read on this or another forum and got me thinking about it. That's my only concern. I will probably take my chances though.

I'm also looking at your rack idea. It may be what I go with because of the open wire shelf advantage for keeping the air flowing. The Earthquake Amp will have to go on something other than a 60 lb. capacity wire shelf though, as will yours. I'll probably just place it on the bottom shelf that could be 3/4" finish plywood platform. They are beasts, aren't they?
I'm building my equipment into a closet on an exterior wall and will have a door on the outside to access the back of the rack. The only downside is, if I have to make a cable/wire change while it is raining, I will be out in the rain making changes. It doesn't rain enough where I live to worry about it though.

Questions: What are you doing to exhaust the heat from inside your equipment room and what about air flow throughout the theater room? I’m thinking a vent toward the bottom of my closet and a fan toward the top to blow the hot/warm air out. I’m not sure what to do about air flow through the room though. Any ideas? Anybody?
Thanks.

**seattle_ice** · **09-29-09, 06:49 PM**

Quote:

Gregavi wrote:

Actually, I'm not worried at all about potential fire. What I am a tiny bit worried about is, if there ever were a fire, the insurance company could, and probably would, use that against you/me in a claim. It’s something I read on this or another forum and got me thinking about it. That's my only concern. I will probably take my chances though.

Questions: What are you doing to exhaust the heat from inside your equipment room and what about air flow throughout the theater room? I’m thinking a vent toward the bottom of my closet and a fan toward the top to blow the hot/warm air out. I’m not sure what to do about air flow through the room though. Any ideas? Anybody?
Thanks.

If you go back to the first page in this thread you will see the fans I am using to ventilate the equipment room. As far as the theater itself, I bought a 2 ton mini split ductless AC/Heat system with three indoor units. One 18,ooo btu heating/cooling unit will go in the theater, one 9,000 btu unit will go in the furnace/IB area where the hot air is exhausted from the equipment closet, and the third 9,000 btu unit will go in my garage.

**seattle_ice** · **10-05-09, 11:11 PM**

The time between the last post and now has been occupied, partially by a trip to Montana to see the inlaws.

For my birthday, I got my first piece of Theater art in the form of a poster:

View from the In-laws place in Polson. Looking out at Flathead Lake:

Glacier Park @ 7000 ft (Peak is almost 10,000 ft.):

**seattle_ice** · **10-05-09, 11:11 PM**

The next task was to finish my screen and get it all mounted.

I finished the actual display surface earlier in the thread. I used dowels to locate it so you can take it down if you want to get to the speakers, or fix it.

The green tape is just to hold the loose edges from flapping around. You can see the holes where the dowels go, and the holes for the mounting screws. I like using the dowels as the slight friction fit ensures that the screen goes in exactly the place it is supposed to, and doesn't shrink over time from the tension.

So after putting the screen up, I needed to make a dark frame for it. I decided to use a common 3-1/4" mdf baseboard molding for the frame.

After messing with the projector for a couple hours, until I was completely satisfied with the exact location on the screen, I miter cut a frame from the molding that was just slightly (1/16") smaller than the picture in both directions. This was so there would be no white screen showing at all.

Then, while holding the frame pieces in place, I drilled 1/4" holes through the frame and into the screen frame for wood dowels. I used about 8 each on the top and bottom, and 5 or so on the sides. I then glued the dowels in place on the frame, flush with the molding face and sticking out the back, and let them dry.

The screen material is the AT Screen from SeymourAV and the velvet was the velvet they recommend in the DIY section on their website.

I used spray contact adhesive to apply the velvet to the trim.

1. Spray the front of the trim, wait a minute.
2. Apply one end of the velvet, stretch and apply other end, then smooth the whole face.
3. Flip it over, and spray adhesive to the back of trim and the rest of velvet.
4. Pull velvet tight, press into cement, trim ends and edges.

It came out very, very well. Here are the top and bottom, ready to assemble:

**seattle_ice** · **10-07-09, 12:30 AM**

I got the screen frame assembled in my piano room, with the dowels glued in place, and small corner brackets attached. I only used the small corner brackets to control the depth of the pieces, so that the corners remain in the same plane, since the dowels would control the placement.

And the velvet close up - it is much darker when the flash is not lighting it up:

When you stand back and look from a distance, the edge almost just disappears it is so dark.

Perfect. I remeasured, and every measurement on the screen and the frame is within 1/16" of an inch or less.

**rickp** · **10-07-09, 06:59 AM**

Nice job so far! and Red Green would be proud. I wonder what ever happened to that show I liked it, especially the one where he demonstrated how to change a headlight with a sledge hammer!

**seattle_ice** · **10-08-09, 11:47 PM**

My carpet showed up at the store today, so now I just got to pick it up, get the pad, and get it installed.

That will be right after I finish the current project - the Candy Counter!

I am making a small built in cabinet in the corner that will house a fridge, a microwave, some shelves and the lighted candy display.

I got the rough cabinet built and set near where it is going to be installed. There is still a lot of molding that has to go on it, the back door for the candy area has to be installed, and then it has to be finished. If you look closely, you can see the bar at the top of the candy area that will hide the light when it is installed.

Close up of the top (I used veneered lumber so I can stain it and some thick Spar varnish)

And a shot of the backside, where there are some shelves:

The whole thing will get painted the dark brown like the rest of the woodwork. Then I will install some glass, and some shelves, and some empty (model) candy boxes.

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