Build Log - First Home Theatre

[Gonadman2]

It seems OCAU loves a build thread on just about anything so I though I might start this here. I've been planning this theatre for quite a while now (about 3 years) and I finally started construction in January this year. I'm an Instrument/Electrician by trade and have no woodworking skills. Everything I have ever done with timber is from reading online or my own personal experience. So you'll have to excuse the panel gaps at times, but hopefully it won't impact the finished product too much!

The Room:
My room is about 4.2m long by about 3.8m wide. It was deliberately constructed next to the understair space so that a rack could be mounted underneath. The screen wall will be on the windows end.







I did a little 3D model of about what I wanted to achieve in sketchup. This has changed a little as it can sometimes be difficult to get an idea of proportion from a computer screen. Also, the scheme has changed as well. If I can be bothered I might update this model at a later date.



First thing I did was measure the room's low frequency response with my calibrated mic. The first response is my subwoofer measured outside in a big space. The second is with the sub off centre and measured at the proposed seating position. As you can see I have a lot of work to do.





I'm sure everyone is bored of empty rooms and plot curves, so its onto the real stuff.

Construction of the stage:

Laying down the foundation. This is later filled with sand as this will be the subwoofer base. I managed to get a good deal on a heap of 18mm flooring ply, so this formed the basis of the build. Its very strong stuff, and heavy!


Filled with sand to help lower resonance.


Installed the floor cover of the stage.


Bass Traps:
Once the stage was complete, I started framing the bass traps. These are going to house the custom speakers and with the curved fronts their construction was a little more complex than normal bass traps. There was a lot of work in these routing the curved shapes, mounting the frames to the walls and then screwing it all together.



Paint:

In hindsight I shouldn't have painted so early, but I was keen to see what the paint was going to look like, and its easier to have paint on the walls and work over it, than trying to 'cut in' against fabric materials later.

Keen observers will note that I cut out the base of the bulkhead. During the house construction I requested that the bulkhead not to be constructed, but I had to have due to building requirements. So rather than ripping it all down and reconstructing it, I hacked some large holes in it for more bass traps. This also made running the lighting, speaker, power and HDMI cables a lot easier!





I went for a nice clean charcoal shade to remove as much reflective light as possible.



That'll do for now, I'll update with more stuff later...

[MellowFellow]

Looks like you're exploring lots of interesting ideas in this build. The little stage already looks great and I'm very keen to see details on the speakers you'll be mounting in the bass traps.

I'd be tempted to fill the bass traps early and take another measurement to see if it helps with your 40Hz peak. If the planned front traps don't do enough you may be able to create membrane traps in the bulkhead to target that particular problem.

Can't wait to see progress!

[Gonadman2]

Originally Posted by MellowFellow

Looks like you're exploring lots of interesting ideas in this build. The little stage already looks great and I'm very keen to see details on the speakers you'll be mounting in the bass traps.

I'd be tempted to fill the bass traps early and take another measurement to see if it helps with your 40Hz peak. If the planned front traps don't do enough you may be able to create membrane traps in the bulkhead to target that particular problem.

I considered membrane traps, but they look quite complicated to build. Maybe, but its already sounding a lot better than when I started. I want to get the carpet down so I can control the top end a little more at this stage. I find it hard to hear the bass, when there is a lot going wrong through the more 'ear sensitive' parts of the spectrum. I have a lot of thanks for Paul Spencer from the stereonet forums for putting me onto bass traps and room treatments in the first place.

Originally Posted by MellowFellow

Can't wait to see progress!

Ask, and thou shall receive!

Lighting:

As I had previously completed the trap framing, I had to plug the windows to perform any more work to the front stage. This was another reason why I wanted to get the paint down. So with the windows plugged with 18mm ply, facing painted white (good luck to the bloke that tries to break in!), I really really needed some lighting. Fortunately I had thought ahead, and picked up 6 x 6W GU10 LED downlight kits. These are installed into the bulkhead around the outside, as I plan to build a false star ceiling in the centre.

This shot was taken without the flash and is more indicative of the colour.


Front Speakers:

For some unknown reason, I did not take any photo's during the construction of the speakers. I can't remember why, I think it was over the easter break, and I was making the most of the time that I had.

They comprise of the following:
1 x Dynaudio Esotar Tweeter T-330D
4 x Aura NS-6 Midbass drivers.

The enclosures are 125L sealed, with the woofers wired in a series/parallel configuration giving 4 ohms. I wanted effortless, smooth midrange for theatre duties and these things deliver in spades. With 4 woofers they are able to move plenty of air while sustaining very low distortion levels - perfect for my high efficiency application. Given that these are only 6" mids, they cross over very nicely in the 2-3khz range.

The Esotar tweeter is good for about 94db/1w/1m and is very highly regarded in audiophile circles. With a resonance that allows it to play very low I believe this tweeter is an excellent performer in 2 way applications.

Currently I have them running off a minidsp 2.5khz/18b/oct crossover, with the mids 5db lower than the tweeter. I am probably going to move that to 5.5db once they are covered but they offer a very relaxed and easy to listen to sound, that will comfortably play very loud.

[Reaper_1994]

Looking good. Maybe better to resize the pics or use facebook or even OCAU Pix to host them

Will you be running the single sub? For a theater room I, personally, would put a sub on each side for action movies with lots of "BOOM" or horror movies like Paranormal Activity that has the low end for when something is going to happen.

Also, what about surround/rear speakers?

[Gonadman2]

Originally Posted by Reaper_1994

Looking good. Maybe better to resize the pics or use facebook or even OCAU Pix to host them

Will you be running the single sub? For a theater room I, personally, would put a sub on each side for action movies with lots of "BOOM" or horror movies like Paranormal Activity that has the low end for when something is going to happen.

Also, what about surround/rear speakers?

I'll get to the subs and surrounds... Still got a bit more to update on first.

The subs will be a pair of either Adire Audio Tumults (I already have one and can source another) or Peerless XXLS 12's. Probably going to go with the Peerless subs as they are $300 cheaper for a pair, than it is for the extra Tumult. But I do like the Tumult I already have. Decisions...

The surrounds will be 4 of these: Sten II

They use the Aura NS6's as well and are plenty efficient. These will come later.

[MellowFellow]

Nice. I'm guessing the empty space in either trap will be a sub, right? Interesting choice of front speakers - I don't have much experience with line arrays but with a ~1m source for voice I expect they'll give the 'big' sound you experience at a real theatre.

Originally Posted by Gonadman2

I have a lot of thanks for Paul Spencer from the stereonet

I wonder if Paul knows how many people he's influenced... My front speakers are one of his designs.

[oculi]

I'd very highly recommend putting the seats in the centre of the room, but then again i'd probably just have a single armchair up front for the ultimate in selfish indulgement.

Are you going to paint the door? could hang a curtain to cover it i guess, what else are you planning for room treatment?

[Brooa]

Originally Posted by Gonadman2

Front Speakers:

For some unknown reason, I did not take any photo's during the construction of the speakers. I can't remember why, I think it was over the easter break, and I was making the most of the time that I had.

They comprise of the following:
1 x Dynaudio Esotar Tweeter T-330D
4 x Aura NS-6 Midbass drivers.

The enclosures are 125L sealed, with the woofers wired in a series/parallel configuration giving 4 ohms. I wanted effortless, smooth midrange for theatre duties and these things deliver in spades. With 4 woofers they are able to move plenty of air while sustaining very low distortion levels - perfect for my high efficiency application. Given that these are only 6" mids, they cross over very nicely in the 2-3khz range.

The Esotar tweeter is good for about 94db/1w/1m and is very highly regarded in audiophile circles. With a resonance that allows it to play very low I believe this tweeter is an excellent performer in 2 way applications.

Currently I have them running off a minidsp 2.5khz/18b/oct crossover, with the mids 5db lower than the tweeter. I am probably going to move that to 5.5db once they are covered but they offer a very relaxed and easy to listen to sound, that will comfortably play very loud.

looks nice man! had you thought about designing some sort of horn for your fronts? and why not build your own subs?

[HumbleBum]

Subbed.. This is going to be epic. Looking at doing my own soon.

[phantom220]

This looks amazing! Can't wait to see more

[Pugs]

also Subbed..

[mortal]

Subbbbbbbed!

Want to see MOAR photos

[Frostex]

definitly interested in this one. lots of good ideas to steal, i mean get inspiration from

[Audionut]

Going to enjoy seeing you finish this.

[Gonadman2]

Originally Posted by oculi

I'd very highly recommend putting the seats in the centre of the room, but then again i'd probably just have a single armchair up front for the ultimate in selfish indulgement.

Are you going to paint the door? could hang a curtain to cover it i guess, what else are you planning for room treatment?

I won't get away with a single seat, the mrs would kill me! We are very social movie watchers, so will probably be going a lounge of some sort. We have a Tornado Super Corner already so that will initially be the seating of choice. Providing it fits of course.

The door will be painted, but I want to remove them first so I can sand them down and paint them properly, a job for another day. At this stage I want to get the messy stuff sorted, so I can minimize the amount of saw dust coming through the house.

Originally Posted by Brooa

looks nice man! had you thought about designing some sort of horn for your fronts? and why not build your own subs?

I did think about this, I almost pulled the trigger on some 18 sound drivers, but in the end I got 20 NS6's for $8 each and they are a proven performer. The semi-line array suited the application more as well, than a single point source.

And of course I'm building my own subs!

Sub Enclosure:

In my model I was going to go for a squared off sub enclosure, but IRL this didn't look so good. In the end we went with a curved front to match the stage. This made construction much more time consuming, but I think the results are worth it.

In this shot I had knocked up the frames.


I finally got the garage back, so I was able to clean everything out of the room too.


Over the last couple of weeks I've been working on the panels that will cover the bass traps. The mrs and I have spent a lot of time working out the scheme, and we'll be going with a wall colour match for the stage and pillars using Rim Fabrics Trilogy One, which is an Acoustically Transparent fabric that offers very good coverage. Don't be alarmed at the huge swathes of black in here, there is plenty of accents and lighting yet to be installed. But I need a nice clean base to work from.

The trim panels are 3mm MDF with the open sections covered in aluminium flyscreen material stapled to the MDF.



Once I got those up, I started covering the Subwoofer section. I'm sure I have a picture of the front of the subwoofer enclosure without the panels, so I'll try and get some more pictures of that. In this picture I'm still working on the trim fabric.



So that's where I'm at as of early July. Moving forward I'll try and document my progress a little better.