Build Your Own Stealth Cinema: Part II

Owning a dedicated home cinema is the ultimate goal for any hardcore cinephile. The easy way to get one is to visit a pro-installation company and commission them to spec and create your dream den. Slightly more challenging is to do all the work yourself! But just how tough is it?

HCC's editor took up the challenge to create a high-performance viewing room. In this second part of his tutorial, he completes the building work, having built subwoofers into the the walls and used acoustic plasterboard and Green Glue to contain future sonic shocks. Now the time has come to really have fun...

1 Previously in this D.I.Y Home Cinema series, we showed how we battened out the walls of our once cosy living room to accommodate in-wall Definitive Technology speakers. It soon became clear that other minor structural tweaks had to be made, including the widening of the bay window area. As this will be the seating area, I concluded that this had to be as wide as possible to accommodate the curved sofa I planned; a brick-width was removed from each side of the bay.

2 The space between the studwork and original wall are padded with standard loft insulation material – the idea being to catch any debris that might dislodge when the plasterboard went up, and to bed down cabling and thereby prevent rattles. The padding would also minimise air-travel around the two Velodyne in-wall subwoofers. For maximum rigidity, acoustically dense Gyproc Soundbloc plasterboard was chosen. Some areas of the room have two-layers of Soundbloc, with a filling of Green Glue, which helps attenuate sound when it travels through the boards.

3 All the cabling had to be finished prior to final plasterboarding. For both the video interconnects and speaker cable, I chose IXOS. It’s important to get the balance right between cable integrity and sheer flexibility when running cables behind walls. While you should avoid cheap bell-wire, it’s easy to over-specify speaker cable only to find the cable is too rigid to be weaved around studwork. The loudspeaker cable chosen for this job was XHS523 Parallel Geometry low-resistance speaker cable, which has the girth to satisfy audiophile concerns but is relatively easy to thread. The heavy gauge Ixos HDMI cable was a tougher proposition but it was anchored to the studwork without too much difficulty.

4 Handling all the lighting requirements for the room was a system from European custom install favourites Niko. Four dimming circuits allowed for a variety of lighting configurations. With literally hundreds of meters of Cat5 routed out of the room and into the adjoining garage, it was here that the heart of the system would be based. A custom bank of Niko Nikobus control boards was built by RajVar Technologies. These were housed in their own cabinet.
During the initial build period team lead Raj Varsani laid additional Cat5 cable to adjoining rooms. Some of this would enable an existing wired network in the house to be further extended, even to the point of facilitating a server in a boot room at some point, while the rest could be used to bring other elements of the house under Niko control. One possible option would be to bring elements off the house's home security under light-switch control. The cool thing about home automation is that once the Cat5 is in, only your imagination (and budget) is the limit.

5 Finally, the room is then plastered over and the project really begins to take shape! When dry, the walls are painted white. Actually, this is probably the worst colour you could choose for a home cinema. Light bouncing from a projection screen will radiate off a white wall, brightening a room when it should be at its darkest. However, compromises have to be made, and if the lady of the house wants a white room, she gets a white room. In truth though, the effect is not disastrous. And it could be argued that a media den that may well be used simply for listening to music shouldn’t feel preternaturally gloomy. Ultimately, the wall will be enlivened by acoustic panel treatments, so it won’t look too plain

6 With a suitable cavity carved into the ceiling, Screen Research’s acoustically-transparent screen is prepped for installation. What I didn’t realise when ordering this 110in monster, which has a width of 2,794mm, is that the actual casing measures in at 2,994mm. Once unboxed I find that it only just fits the width of the room.
The casing employs a motorized trap-door that, once installed, sits flush with the ceiling. It has to be installed before any fabric roll is fitted. A bespoke mounting kit for the casing is supplied with the case, but proves unusable, so Builder Dave (resplendent in Union Jack shorts) just drills the roof of the casing. His plan is to screw it directly into the ceiling joists. Once drilled, the case itself must be meticulously cleaned of aluminium debris before it is fitted. Any rip to the fabric from an errant shard would be heartbreaking. The casing is so heavy it takes four of us to wrestle it into position. Amazingly, it fits perfectly. All respect to Builder Dave!

7 The newly-plastered ceiling is now cut open for the in-ceiling rear speakers. Four Definitive Technology Reference UIW RSS speakers will be used to create the rear soundstage. These speakers employ a unique angled bipolar-array which creates an enveloping soundfield directional enough for multi-channel music and spatial effects, yet diffuse enough for genuine surround movie ambiance.
I personally avoid direct-radiating speakers for rear use, finding them much too directional and distracting. With friends or family in for a screening, someone is always going to be too near one of the enclosures. Unlike dipoles, bipole speakers feature multiple drivers that operate in phase. Traditional THX-style dipoles have two drivers that are out of phase; dipoles typically are placed on the side-wall, with the viewer sitting in the null point that’s created. The technology works well for movies, but less so with music playback. To get around this, some manufacturers build speakers with a switch that allows you to toggle between bipole or dipole output. As I intend to spec a DVD player capable of SACD and DVD-A playback, bipoles are the way to go.

8 Note to self: prior to plastering, the position of the loudspeaker cable and the timber framework must be carefully noted! My advice is to make multiple measurements at this stage, drawing a representation of the speaker position on the ceiling, because when you cut into that fresh plasterboard you won’t want to get it wrong.
When the speaker cable is attached to each enclosure, I blob flexible sealant onto every fixing. This will help ensure that the terminals don’t relinquish their grip on the cable over time.

9 The rear back speakers will be positioned either side of the projector mount. These should be located quite close to each other.
When planning your placement, imagine sound being steered from the side to the back of the room, in a sweeping curve that ends up behind your head; that’s the kind of sonic imaging you must aim to re-create.

10 Once the projection screen casing is secured to the ceiling joists, the power supply (which you’ve remembered to run up to the casing behind the wall, haven’t you?) connects to the trapdoor’s motor. The projection case is now ready to accept the screen fabric.

11 The fabric itself arrived some time after the casing, in yet another huge container. I decided to use Screen Research’s THX-certified ClearPix2 woven fabric. Although it will lower directly in front of the in-wall L/C/R speakers, audio fidelity is unaffected. The fabric comes with a black backing, certified by both THX and the ISF, which is designed to suppress reflections behind the screen and boost the perceived contrast ratio. The picture quality delivered by this fabric is absolutely outstanding and I can’t wait to get it in place. Obviously, it needs to be handled with care...

12 The front-facing Definitive Technology Reference UIW RLS11 speakers are finally secreted, and screwed, into the timber frame created as part of the screen-wall. Note that the reset well has been tiled with black slate and had a plasma screen mount fitted. The black slate was chosen to provide a stark contrast with the white walls, thereby create a striking monochromatic effect. The slate’s uneven surface should also complement the smooth plasma screen and provide some subtle shadow effects when the system’s backlight is engaged. The plasma screen chosen is Panasonic’s TH-65PX600 65in model, a mind-blowing 1080p panel with high-quality stereo speakers for general use. Originally, I planned on using Panasonic’s own-brand mount for the job, but once in I found that it stood too far off the wall. Instead, I opted for a fixing from leading screen-mounting operation Future Automation. Its PF65 model is just 30mm thick and would allow the screen to sit much closer to the wall than the official alternative.

13 The grille covers are finally fitted to the in-wall Velodyne subwoofers, and become the only visible evidence of the hidden bass-behemoths. The grilles themselves are a metal mould, and while they ping out easily to allow the frame to be wall-mounted, they prove to be the devil’s own job to return. Neither of the two go back on properly. When I whine like a baby after cutting my finger trying to force them back, Velodyne’s UK distributor RedLine pops around, convinced I’ve done something wrong. I haven’t. RedLine is also unable to fit them back flush. I conclude that it’s a strangely poor piece of design for Velodyne’s SubContractor range. Has no one else in the pro-cinema industry complained about them?

14 When it comes to choosing an aircon unit for the cinema room, two factors were deemed paramount: design and operating noise. Satisfying both is Japanese specialist Daikin. The company’s Award-winning FTXG-35EV unit is A-rated for energy efficiency, stands just 15cm from the wall and has an operational noise of just 22dB when cooling. This makes it virtually silent in operation. The outdoor unit is similarly quiet in operation, running at approx 44dB. The installation was handled by London specialists Cool Connections. The major DIY retailers all have their own brand of aircon units, usually at really aggressive prices. However, the difference between the approaches is like chalk and chilled cheese. Once you’ve seen (or heard) a Daikin in action I doubt you’ll want anything else. It’s an indulgence I can’t resist.

15 Perhaps the toughest job when finishing the room was mounting the plasma TV. Weighing in at a massive 79kg, the screen had to be held upright in order to plumb in all the connections (HDMI, component, Scart, aerial) before it could be hung and secured in place. Simultaneously, that part of the Future Automation mount which bolts into the back of the Panasonic screen was fitted out with Apollo LED light bars from online retailer neon-lights.co.uk. This all took some synchronizing, not to mention half-a-dozen hands. The LED light tubes come in a variety of sizes. For a screen as big as this I opted for 4x 24in. Rather than provide an Ambilight-style backlight, I intended to bounce coloured light off the recessed wall. I had my fingers crossed at this point that everything would work, because once mounted, the TV wasn’t going to be easily moved

16 Adding considerable sophistication to the overall install was the provision of an electric curtain rail from market leaders Goelst. Goelst produced a bespoke aluminium track for the bay window (finished in white to blend with the ceiling) that fit like a glove. Meanwhile RajVar Technologies, the specialists looking after the lighting and home automation, provided a suitable spur for the motor. Although Goelst’s 6200 G-Rail track system comes with its own programmable remote control as standard, my plan was to integrate it within the Niko smart lighting system. As a consequence, it would be possible to open or close the curtains from the light-switch. Able to haul upwards of 15kg, the Goelst would have no problem opening and closing the black drapes with blackout backing that were eventually hung in the room

17 The projector chosen for the installation is a Mitsubishi HC5000 (now superseded by the HC6000), an astonishingly quiet 1080p LCD model, capable of remarkable visual clarity – typically priced at just £2,000. I was considering a DLP model, but rejected them because of fan noise. The PJ itself sits directly above the seating position. It was only when all the inputs of the HC5000 were duly connected did it occur to me that I really need not have run so much video interconnect to the PJ in the first place. A single HDMI and supplementary component lead would have sufficed; even mid-range AV receivers can now upscale all sources to 1080i or 1080p and squirt them out via the HDMI connection.

18 The room is then carpeted (don’t opt for bare floorboards, it’ll wreck the acoustics of the room) and the seating duly arrives. Although there are a number of custom install and CEDIA dealers bringing dedicated US-style cinema seats into the UK, their physical size (the chairs, not the dealers) and price ruled them out of this job. My aim was to accommodate four in the bay-space and my budget was at breaking point. So I turned to DFS, the furniture superstore with perennial sales. As it happened they had just the sofa, a curved Vetta electric four-seat recliner for £1,098. Even having removed the brickwork early on, the sofa only just fits into the bay.

Next: Our cinema room is dressed and ready to rock - but does the theoretical design really deliver the goods? And what can we learn from the process?

COMPANY CHECKLIST
HCC’s D.I.Y. home cinema used the following kit and service providers...

Velodyne
SC-IW SubContractor in-wall subwoofer, £815 SC-BB backbox, £145 Velodyne SC-1250 power amp, £850
www.red-line.co.uk
Tel: 0131 555 3922

Definitive Technology
Reference Series UIW RLS 11 L/C/R speakers, £650 per speaker Reference series UIW RSS 11 surround speakers, £599 per speaker
www.pulsemarketing.org
Tel: 01279 718 884

Screen Research
THX Acoustic Transparent in-ceiling trapdoor screen (product code MS-IT-110-178-2W-B) inc motor controller, £6,315
www.pulsemarketing.org
Tel: 01279 718 884

Niko Home Automation & Lighting Systems
www.usd.uk.com
Tel: 01525 877707

RajVar Technologies
Smart lighting and home automation system integrators
www.rajvar.com
Tel: 020 8206 0979

Future Automation
PF-65 Plasma mount, £200
www.futureautomation.co.uk
Tel: 01438 833577

Goelst
G-Rail 6200, £price on application depending on requirements. Can be integrated with the Niko Smart Lighting system
www.goelst.nl
Tel: 01423 873002

Daikin air conditioning
FTXG-E air conditioner plus external unit, inc. installation, £2,500 approx
www.daikin.co.uk
Tel: 0845 6419000
Cool Connections
Tel: 01708 724165

Green Glue
Case of 12 857ml tubes, £98
www.greenglue.co.uk
tel: 01303 230944

Ixos Cables
www.ixos.co.uk
tel: 01844 219 000

And last but not least..
Builder Dave Ryall
Tel: 07957 488 002