The installation of a basement home theatre can quickly transform into either a client’s greatest dream or an installer’s worst nightmare.

While the reduced amount of natural light and detached location from the rest of the house are favourable features, the basement is often a difficult space for installers to work in, particularly if the room hasn’t been designed as a home theatre from the very start. After all, who needs to add solid concrete walls and dead space to the headaches of installing a home cinema?

For Melbourne-based installer Technology in Design, the challenge to develop an existing basement into a high-end home theatre was no easy feat.

“The space is used as a multi-purpose room rather than a dedicated home theatre – it’s set up for gaming and general entertaining,” Technology in Design director Steven Hill says.

“The husband is particularly into his music so the audio had to sound good, but all the walls were concrete and it sounded incredibly bad initially. They also wanted to retain that large-room feeling, so we went to quite a length to fix all of the problems.”

Fortunately, the team from Technology in Design was familiar with the awkwardness of this long room. Before the current owners moved in, they were contracted to install a small amount of structured cabling into the home and had already pre-wired the basement, paving the way for a future home theatre.

“When the current owners bought the home, we were referred to them as a company that could create a home theatre. We did a house demo with Genelec speakers for about a week so the couple could decide if that was the quality of sound that they wanted – and ended up winning the job,” he says.

That’s when it all began. On top of working with existing solid walls and a lengthy basement, Technology in Design also had to factor in the owner’s request to keep their existing furniture and ensure the room was well-lit.

“Basically we were trying to balance a really high ambient light level from the downlights with white-coloured walls, without decreasing the room size, and creating a really punchy and high-quality video and audio experience. It was like a worst-case scenario in terms of lighting and acoustics.

“The couch has an aisle where the normal ‘sweet spot’ or ‘money seat’ would be in regards to getting the best video and acoustic experience, so we did a lot of design work in drawing up the joinery and coming up with different concepts to get the best result from the home theatre, which is located at the front of the room.”

The acoustic panels were made in-house so the colour could blend with the carpet, walls and ceiling. To maintain the big-room feeling, the team designed larger panels that were 600mm wide and stretched from the cornice to the skirting board.

Working with a limit of 100mm in depth, they chose a semi-rigid fibre glass as the in-fill. Steven says this could provide the correct Gas Flow Resistance (GFR) for that depth, which defines how much resistance a material can present to air moving through it to a specific depth.

“We also designed the home theatre cabinet and the screen above that is ‘floating’ – it sits forward about 600mm on cantilevers so you can see between the screen and the top of the cabinet. Behind this we have more acoustic absorption, with the centre channel mounted behind that acoustically transparent fabric,” he says.

“A subwoofer is also mounted in the joinery and vented through the top. This allows for acoustic venting for the sub as well as heat from the equipment in the cabinet.”

He says a JVC X3 projector was chosen as it could be calibrated and still produce an accurate image with maximum brightness.

“While there is no natural light coming into this theatre, there are quite a few downlights throughout the room that shine directly on the screen – but even when the room is fully lit, you can still get a completely watchable, very punchy image.

“The room’s colour scheme was also going to affect the contrast negatively with the ambient light on, so instead of going for a more sophisticated projector, we went for the X3 and put the budget toward the acoustics, speakers and screen.”

A micro-perforated Stewart Firehawk film screen was selected as it could provide a lot more gain than a normal widescreen. Being grey-based, Steven says it was also essential to retain a high degree of contrast with a high amount of ambient light.

“The speakers we put in were Genelec 8250s, which are a digital signal processing (DSP) model. We put a microphone in the main seating position and calculated all of the room’s frequency response to make sure that seating position wasn’t going to interfere with bass cancellation,” he says.

“That allowed us to optimise the DSP and equalisation in all three of the front speakers and retain the ‘money seat’. So even though you’re off-axis from the centre, everything is perfectly adjusted so it still feels as though you are sitting in the centre.”

Steven explains that the reason for this is that the Genelec speakers have a good wave guide on its tweeter. He says it is usually very directional and controls the wave front of audio that leaves the speaker to provide a larger and more consistent off-axis frequency response.
“The best listening experience is definitely in the first half of the room. We got the reverberation time down to 40ms where the seats are, whereas before it was about 70ms which is very high. But even if you are at the back of the room, it is still quite enjoyable,” he says.

Considering that a big part of this project had to be designed from scratch in order to adhere to the design brief, Steven notes that this is where his attendance at CEDIA courses came in handy, particularly one on home theatre acoustics that was conducted by audio pioneer Floyd E. Toole in the US.

“The great thing is that the measured result at the end of the job very closely matched the predicted results during the design phase. At the end of the day, the real room acoustics and ambient light issues had to be addressed first in order to get the client’s desired result,” he says.

“I think the final outcome surpassed everybody’s expectations, because the room itself was the biggest problem in this particular installation. The Pronto-based control system has been very reliable so far and once you’re in the room, there is a good balance of aesthetics and technology – it will still look and sound as good as it does today in 10-15 years. It was difficult to meet the goal but we achieved it in the end.”

Technology in Design
www.technologyindesign.com.au