Another place

Anna Mitchell finds out how to create a cinema room where technology melts away, leaving you totally inside the world a filmmaker has created.

In the realm of home cinema, the pursuit of immersion is paramount. It's about transporting oneself into the heart of the action, where the outside world fades away. But achieving true immersion involves a delicate interplay of technologies and techniques, each aimed at eliminating distractions and enveloping viewers in a seamless AV experience.

Beyond resolution

There’s a tendency to focus on resolution when it comes to display technology, but true visual immersion extends far beyond pixel counts.

With the correct set up Ben Goff, technical director at Cinema Lusso, questions whether anyone would be able to gain a noticeable difference with 8K and adds: “We have a native 4K projector in our cinema and quite often we demonstrate clips that are regular Blu-ray 1080p; it’s amazing how good lower resolution content looks on a good projector. Resolution is only part of the puzzle.”

That ability to really get contrast from deep blacks to bright highlights, to get dynamic range through an HDR image is more important than resolution argues Goff: “If I pick the right content and flick between 1080p, 4K and 8K, I could probably fool you but, when it comes to contrast, you’ll instantly see the benefit.”

Aspect ratio is also a huge consideration when it comes to immersion. Goff says after a trend from Hollywood to go widescreen, the latest move from directors is to want height as well, with recent major releases (think Oppenheimer) designed for Imax.

MovieCore showroom featuring MAG Audio and Ascendo Immersive Audio speaker solutions with layouts supporting Dolby Atmos, DTS:X and Auro3D | Credit: ARLED Cinema

“These films are hugely immersive but for residential we often pick a screen size and clients hate black bars. We do sell masking screens but they aren’t low cost,” says Goff. “Many of these releases also swich aspect ratio scene to scene so you’ve also got no time for the bars to move.”

Regardless of budget, most residential cinema rooms are more limited by ceiling height than they are by width, which can make accommodating Imax formats properly basically impossible, so compromises inevitably must be made.

But, if you do have the ceiling height to play with, Goff says the immersion benefits are significant. “We’ve built a cinema demo room here at Cinema Lusso and it’s nearly 3.6m tall. When you watch Imax content in there, it’s incredible. It fills the whole of your field of view.”

Crafting sonic realms

Whatever your display choice there’s one thing for sure: in almost all home cinemas all the visual cues will come from in front of you. This means there’s some heavy lifting for audio to envelope a viewer from all angles.

“The human auditory system was trained over tens of thousands of years in nature to be alert of any dangers that happen around us. We can determine very angular changes in sources and, even if we close our eyes, we can pinpoint a sound source with precision,” says Geoffrey Heinzel, managing partner of Ascendo Immersive Audio. “The more detailed this audio rendering happens in a reproduction audio system, the more precise the recreation of that audio bubble is.”

One of the ways the human auditory system is so fine-tuned, explains Heinzel, is in timing as that determines the distance any noise is away. “We can perceive a difference of .1 of a millisecond which is just a few millimetres,” he says.

Apart from marvelling at how amazing the human the brain is, this poses challenges for speaker set ups when you think that a 10-person cinema means 20 ears and therefore 20 points to reach with the correct auditory information. Any information that doesn’t arrive as it should indicates there’s something wrong to the listener and reduces feelings of immersion. 

It’s something that, from its foundation, Ascendo has set out to solve. “We design and make point source coaxial loudspeakers. This means that sound from the tweeter and the mid-range arrives at the same time to each of these 20 positions in the home theatre,” says Heinzel.

For Nick Fichte, business development director, Home & Yacht at L-Acoustics, audio is a key tool in separating viewers from reality.

“As a loudspeaker manufacturer it’s very easy to get hung up on having high sound pressure levels but it’s important to note that having a system that’s powerful also means you get wider ranges of dynamics.

“It’s the difference between quiet and loud where you can distance yourself from reality. In a quiet scene, if you are hearing the creaking of the floorboards or the wind blowing through the leaves, you get a sense of realism. A powerful system allows you to feel those details.”

ARLED Cinema - MovieCore showroom featuring Ascendo Immersive Audio Director Series above and below screen speakers

Formats, standards… and RP22

When it comes to immersive audio Dolby Atmos has runaway as the dominant format, particularly in terms of consumer awareness. Other formats are available (Auro-3D and DTS:X to name just two), but nowhere near as ubiquitous.

David Meyerowitz, technical sales manager international at Trinnov Audio, has an idea of why that’s the case: “Trinnov actually started out looking at 3D sound but quickly realised it’s such a huge endeavour to change the world of audio with new formats,” he says. “In reality, it’s only a company like Dolby with deep pockets that can achieve that.”

What’s interesting here is that it led Trinnov to consider what problems it could solve that were related to the work it had done on 3D audio. 

“If we want to further improve 3D production then we need a way to tune the speakers as best we can,” continues Meyerowitz. “If you want to create immersion, you don’t want to hear the speakers, you want to hear a bubble of sound. It’s about having everything in order, with the right level and the right timing. If every component that is part of the system doesn’t play cohesively, you are going to hear one speaker that is drowning out the rest, that’s going to divert your attention and it’s going to ruin the experience.

“When we tune a system with electronic processing, we start with proper physics which includes speaker and subwoofer placement according to our guidelines. Then the processing ensures that all the speakers play together seamlessly and that’s how you do justice to the great content that has been created in these new immersive formats.”

When it comes to the various immersive audio formats Meyerowitz says it’s a constantly moving target that Trinnov watches closely and, where appropriate, accommodates. “Ultimately as a consumer you shouldn’t worry about formats, you just want a seamless experience. It’s our job to ensure we cover and playback the content they are going to listen to however it’s encoded.”

With Dolby Atmos now a household name, most professionals are happy with the experience it delivers for both movies and music. But there are concerns. Not all Atmos systems are created equal. The label is variously applied to multi-speaker set ups that fire sound from ceiling and around the listener, right down to low-cost soundbars.

L-Acoustics X8 and X4i 2-way passive coaxial loudspeakers and Syva Low 12-in subwoofers were installed by Premier Group in this home theatre

Goff believes the soundbars have their place but says the industry must do a better job of being realistic about the experience they will offer a listener. “I think soundbars do a really good job,” he says. “But if we miscommunicate their capabilities, suggesting that a £300 unit will ‘bring the cinema home’ we have a problem.” 

This is perhaps why RP22 (the immersive audio recommended practice from CEDIA) has resonated so well with the industry as it clearly defines what you will experience from the investment you make.

In the Cinema Lusso demo cinema, Goff and his team have put RP22 into practice, creating, from the ground up, a Level 4 (the highest level) space.

“We have 19.1.10 sound system and the .1 for the LFE channel is managed by 12 subwoofers,” says Goff. “On our front wall, we have six 21-in subwoofers and then another four 21-in subwoofers on the back wall and two 32-in subwoofers as well. They can also use Trinnov’s Waveforming technology [a tool for controlling very low frequency acoustic fields], so we create a planar wave that moves through the room. We’ve got huge control of the bass.”

Delving deeper into the reasons why bass control is so important, Trinnov’s Meyerowitz says: “All the psychoactive cues you need to get from the speakers above and around you are cleared up by clean bass. If you implement Waveforming, it’s going to get bass in order and the masking at the upper end of the frequency range disappears. If bass is out of control, it smears the mid and high frequencies, and the immersion drops.”

Meyerowitz adds: “Within RP22 is a parameter for seat-to-seat consistency in the low frequency. Depending on the level you want to achieve, you cannot have more than a +/- Xdb difference below 100Hz across seats. Waveforming can exceed the Level 4 recommendation for all seats when implemented with its highest performing layout. This is something that is simply not possible with passive acoustics or other active correction systems.”

Fichte says: “As soon as the recommended practice was released, [the L-Acoustics] application engineers immersed themselves in the document and they’ve adapted our system specification reports to incorporate the sections of RP22 which we can influence, highlighting what the performance of the loudspeakers will be.

“When we do a [home cinema audio] design we lay out exactly the parameters that we can influence. We fact-find with the integrator the level they are looking to achieve, and we design the system around those requirements, making sure it achieves them all.”

Trinnov Audio WaveForming

The challenge with LED

Projection isn’t the only display technology on the market thanks to developments in the LED space. While DVLED displays offer dazzling visuals, they present unique challenges in achieving immersive sound due to limitations in speaker placement.

“Whether you are talking about immersive sound or low frequency reproduction, the fact that you have one big non-acoustically transparent object on the front wall where all the information is coming from is a big challenge but with the right tools can produce amazing results,” says Meyerowitz.

However, he adds, it’s a challenge worth accepting as, due to the multiple benefits of LED technology and continually falling prices, the trend is certain to grow. Trinnov has racked up multiple installations in the space, collaborating with other technology manufacturers to overcome the challenges posed by large format LED displays.

Also developing solutions for this space is Ascendo. Without being able to place speakers behind a screen, Heinzel says you must create a phantom centre in both the horizontal and vertical planes, installing left, centre and right speakers above and below the screen.

“We get great results but of course it’s double the effort, double the amplification and double the processing,” he says.

Fichte at L-Acoustics says the company draws on its live sound heritage to navigate the challenge of audio in home cinemas with DVLED screens. “When you go to a concert you have musicians on a stage and, as an audience, you want the sound coming from where the artist is. With left/right PA hangs, as stages have gotten bigger, you’re using the summation of the two to get mono coverage across the whole audience. Back in 1992 L-Acoustics pioneered the use of line array technology to make that happen.

ARLED Cinema - MovieCore - including Ascendo 80-in infrasonic subwoofer

“To try and make that more realistic, and we use the term hyperreal for this, we developed a spatial technology called L-ISA for live performances with which you spread speaker arrays – a minimum of five of them – across the front of the stage and the mixing engineer can then take the sound objects that are coming into his console and place them dynamically across the entire stage. Using line array technology with L-ISA, you can cover the front to the back of the audience in more natural, immersive sound.

“In home cinema, essentially the principle can be the same. When we get a project with a DVLED screen in it, we often specify our larger form factor loudspeakers, which use constant curvature technology, and mount them above the screen, angling them at a point where it will throw from right at the very front, all the way to the back of a room with excellent coverage.

“Instead of there being a mixing engineer mixing sound objects live in the room, the spatial mixing has been done in the studio, typically with a Dolby Atmos mix, but the principle is the same.”

Deeper impact

We’ve covered things you can see and hear, but there’s more. Infrasonic frequencies, those below 20Hz, though often imperceptible to the conscious mind, wield tremendous power in shaping emotional responses. When harnessed effectively, they add a visceral layer of immersion that resonates deep within the viewer. While their integration demands space and budget, the payoff in terms of heightened sensory engagement is undeniable.

It's an area worth exploring with Heinzel noting that “There is so much very low bass content in all the movies that are being produced now. If you can reproduce that it opens up another world and gives a sense of space in a system.”

“We’ve manually tuned and calibrated infrasonics into the Trinnov Waveforming system within our demo cinema,” says Goff. “It’s something you can’t hear, but you can feel it. Subconsciously you know it’s there and it can have an emotional impact on you.

“Immersion isn’t about how good the screen is or how many speakers you’ve got. They’re important but immersion is how deep does that system takes you into the world filmmakers created. Infrasonics is another tool in that armoury.”

Ascendo is one of the leaders in this space and Heinzel continues to outline some of the reasons why integrators need to enter this space with their eyes open to manage client expectations and ensure an installation will deliver the desired effect.

“Let’s assume you have a subwoofer that produces 40Hz, and now you want to reproduce 20Hz at the same level. You need to quadruple the cone area or the power to be able to produce the same frequency one octave down,” he explains.

It’s a simple quadratic function that has anything but simple implications in real-world applications.

“If you use four 18-in subwoofers in a home theatre to reproduce 40Hz, you need sixteen 18-in subwoofers to reproduce 20Hz at the same level,” Heinzel says. “And then if you want to reproduce 10Hz, you would again need to quadruple that so it’s 64 18-in subwoofers to reproduce 10Hz at the same level.”

Ascendo manufactures subwoofers with cone sizes up to 80-in which require cabinets to be ideally poured from concrete within a client’s home; you need a dedicated room for the subwoofer. “But if you look at that quadratic function, you can understand why we go to these lengths,” says Heinzel. “They are actually space saving when you compare them to the amount of say 18-in subwoofers you would need to achieve the same effect.”

And that’s only the start. “The human ear and below hearing threshold sensory system becomes very insensitive at ultra-low frequencies. You need to raise the very low bass to perceive it at the same level. In other words, not only do you need to reproduce the same SPL at 40Hz as 20hz, you need to raise it by 6 or 10dB to even perceive the same level.

“Then there is the power part, the amplifier part. We’ve done home theatres where just the bass required 120kW of power. You must understand the needs, the cost and the space requirements to achieve that.”

Pressurisation is a tool that can be used to create the effects required. “Let’s say a room is 10m long, it can only fit a certain wavelength,” explains Heinzel. “In theory there is no way possible to reproduce below 20Hz in 10m long room. However, if you pressurise the room, the differentiation you perceive in your ear allows you to reproduce low bass, the same as in-ear headphones work.”

When it comes to immersive cinema one thing that’s become apparent is you need to have the right technical partners, the correct knowledge and you can’t cut corners. It’s not for the faint hearted, but it’s worth the effort.

True immersion arises from a symphony of visual, auditory, and spatial elements working in harmony to transport viewers to another place. By embracing cutting-edge technologies and thoughtful design principles, the home cinema experience can transcend mere entertainment, becoming a journey into the heart of storytelling itself.

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