NEW CINEMA FROM OLD

Out with the old, in with this new reference-level home cinema wrapped in glorious Art Nouveau trimmings.

Out with a previous cinema, in with this new reference room from Wavetrain Cinemas, wrapped in glorious Art Nouveau trimmings.

This custom home cinema from Wavetrain Cinemas replaced a previous home cinema in the same space. You might think that would simplify things considerably, compared with converting a basement room or starting from scratch with a concrete shell. But as Wavetrain’s David Moseley explains, that would depend on the quality of the original cinema design.

“The cinema as it was had significant issues to overcome,” he tells Sound+Image, “and the space didn’t match the client’s inspiration for the new design, which was a previous ‘Art Nouveau’ cinema we had created. That had been a room with 3.2-metre ceilings, but here the ceiling height of the cinema was only 2.4 metres, and below that there were existing concrete beams and a 70mm drop in the slab at the screen end of the room. That previous cinema design would never work with these room proportions.”’

The ceiling was not the only issue requiring careful forethought. There was no air-conditioning to the room, only an exhaust fan ducted to the outside which was, says David Moseley, “incredibly noisy”. In addition to better air-con, there was a need to deliver a high level of sound isolation. And for the system itself, the client wanted a “reference” AV system, with seating for eight people and a good-sized screen for the viewing distance.

Room design

But such issues are all part of the process for Sydney-based Wavetrain Cinemas.

“We are a complete turnkey cinema company,” notes David. “So we produce all of the architectural drawings for the project, the mechanical and acoustic engineering, and also the interior design. While the ceiling issues prevented us duplicating the cinema which the client had taken as a reference, we were able to go in a slightly different direction and used the Art Deco/Art Nouveau set designs from Superman Returns as an inspiration, then overlaid that with opulent materials such as the aged bronze metal finishes, velvet curtains and art-silk carpet. It really lifted the room.”

Meanwhile there were those fundamentals of room shape, ceiling heights and seating positions to be addressed.

“Normally we would have a rear seating platform of 350mm to deliver the sightlines required to see the screen,” says David. “But here we had the low ceiling height, a 70mm dropdown over the screen, and we needed to create a bulkhead at the front, for the Atmos speakers and to hide the curtain track and lighting. So the screen in this cinema is lower than usual, with the screen image 540mm off the floor. We also needed to create a bulkhead at the rear, for the Atmos speakers and the ducted air-con system. To get sufficient room height as you step up, the seating platform could go no higher than 225mm, and that was a potential problem for sightlines.”

The solution was for Wavetrain to custombuild special daybeds, matching the rest of the seating while allowing the front row to lie down. The sightlines to the screen were then clear from the rear row.

Another major issue was a curved staircase that entered the room. Rather miraculously, there’s no sign of this in the final cinema.

“If we created the platform with the staircase inside the room, it would have been illegal anyway,” notes David Moseley. “We did however need to create space for the AC to enter the room, and also needed space for the bar the client wanted. All of this required that we build out the cinema on one side of the room sufficiently to make it all work and still keep space for eight cinema seats. The ceiling bulkhead covers most of the concrete staircase protrusion, so that only a small part of the concrete is visible and we disguised this to look like part of the ceiling pattern.”

Isolation and air

Sound isolation was a priority for the client, who wanted to use the cinema without affecting the lifestyle of the rest of the home.

“Luckily the room was literally a concrete shell,” notes David, “so we at least had mass on our side for dealing with airborne sound. Structural transmission was going to be the main issue.”

Without the room height to allow for a floating floor or isolated ceiling to be used, some innovative thinking was required. The floor-mounted front subwoofers were installed on their own little floating platform, while the walls were built with a cavity and double-layer construction, including Green Glue noise-proofing compound to further attenuate sound getting into the structure.

“With the front speakers and subwoofers resilient-mounted, and the furring channel system we designed for the walls, it means that the bulk of the energy in the room simply can’t transmit to the structure,” says David. “Then we’ve provided a quiet air-conditioning system that introduced fresh air without compromising this sound isolation. We manufacture a range of AC products specifically for cinemas that are built into the structure to attenuate sound escaping the room, and slow air velocity to eliminate air turbulence, and ensure that the system can never rattle. We also manufactured the custom sound isolation door to the cinema — the entry to the cinema already had a door to the staircase and we designed this area to act as an air-lock.”

With the platform height too low for normal ducting, Wavetrain “treated the cinema like a yacht”, and formed the ducting within the timber structure itself. The ducts were then lined and covered with the flooring.

“We didn’t have the space for an AC fan coil inside the cinema,” says David, “but we were able to use an area in the garage behind the cinema and then custom-design joinery to accommodate the fan coil, equipment rack and projector hushbox. Given we couldn’t take fresh air from a garage that could have carbon monoxide in the air, we reversed the existing exhaust fan, taking a fresh air intake from a shaded area under the eaves into the front of the cinema and on to the rear.”

The audio system

With the client after a cinema that could match commercial cinema performance, Wavetrain proceeded from its usual starting point of placing seats into positions where they share common issues, then positioning the speakers and subwoofers to eliminate the worst problems in the room, while using an acoustic treatment system designed to improve imaging and tighten voices. Bass traps were built into the seating platform and the front corners of the cinema.

“If that’s all done correctly, the final tuning of the system mainly comprises cutting some bass power in the room,” says David Moseley. “Tuning a cinema is the last step, a fine tuning of the system — it shouldn’t be a fix for all the unresolved problems in a room. Good rooms and correctly engineered systems produce great results.”

The goal was for the system to able to play at a continuous 105dB, giving 3dB of headroom so that even at reference level, the system is never strained. Wavetrain specified Elementi Audio’s digital active speakers for the front LCRs, a new brand (see opposite) which positions dedicated amplifier modules close to the speakers, both eliminating long runs of speaker cable and keeping the main equipment rack significantly less populated with heat-producing electronics. Meanwhile the crossover duties are executed in the digital domain, each loudspeaker driver then given its own dedicated channel of amplification.

“Using a digital active system ensures that when the bass drivers are being pushed hard, that strain does not show up in the tweeters,” says David. “The result is effortless power that is incredibly detailed.”

The Elementi speakers used for the front LCR here are the Sirocco model from the ‘Air’ range, with pleated diaphragm tweeters rather than the compression drivers of the Fire range.

“Sirocco is a very unusual speaker in that the waveguide changes based on the speaker use,” says David Moseley. “The left and right speakers toe the sound in 10 degrees to deliver more energy to the seating area and reduce boundary reflections. The centre channel is uniform in its dispersion pattern. This means that the Siroccos don’t need to be physically toed in, while with a 100-degree horizontal dispersion, the coverage across the seats is exceptional.”

The surround speakers were positioned with the tweeters on the top, placing them above ear height. Meanwhile the balanced signals to the 17 speakers and subwoofers in the system are supplied from a 16-channel Acurus Muse processor, selected during a careful rethink after the budget was significantly reduced by the client — after the design stage had been completed.

“We managed that by eliminating the bar, having the chairs built here in Australia, and re-specifying some of the materials chosen”, he says. “We installed the cinema in such a way that the bar can slip in at a later date. We also went from using Elementi all round the cinema to a simpler design using some Triad speakers and the Muse processor. ”

Four subwoofers are used, acting as a single LFE channel and positioned at the quarter points across the width of the cinema room, “all time-aligned and levelled to the middle of the room, then phase/level adjusted