With the spread of big-screen televisions and video streaming services, the way of watching films at home is undergoing significant change. What kind of home cinema do people want in this day and age? Sony offers its response to this question with the BRAVIA Theatre Quad home cinema system that creates a fully fledged spatial sound with just four speakers. The system produces a sound powerful enough to send ripples across your skin, but it was also created with the aim of achieving harmony with the space around it. We spoke to the engineers who developed the system to learn more about the technology concentrated within.
As television formats evolve to focus on "nothing but the image", home cinemas are also becoming simpler and more understated. The design of the BRAVIA Theatre Quad takes things one step further, aiming to be a pleasant presence within the living room, in harmony with the space around it.
The BRAVIA Theatre Quad system creates a spatial sound in the area enclosed by its four speakers. By analysing the acoustic characteristics of the room such as the position of each speaker, the shape of the room, the material of the walls, curtains and furniture this system creates and automatically optimises the sound field. As a result, it delivers optimal performance, regardless of the room's shape and layout or how the speakers have been positioned.
It supports 360 Spatial Sound Mapping (360 SSM), which reproduces the actual sound space in a way that fundamentally differs from traditional virtual surround sound, which only merely simulates human auditory perception to create a spatial effect. With 360 SSM your ears and body experience the same air vibrations as in true surround sound, allowing for an even deeper immersion in the world of film.
By drawing out the full potential of the 360 SSM technology, the BRAVIA Theatre Quad uses just four speakers to produce an ideal spatial sonic space that sounds as if far more speakers have been positioned around the room.
The performance of the BRAVIA Theatre Quad is excellent, no matter which television one pairs it with, but connecting and linking it to compatible BRAVIA models yields an even richer listening experience. All film lovers with BRAVIA televisions should try out the BRAVIA Theatre Quad.
Sound quality and concern for the environment can be difficult to reconcile, but we achieved both through proactive measures taken from the initial stages of development. We replaced nearly all plastics with recycled materials and introduced new innovations, such as creating stand parts that also function as wall mounting brackets. Additionally, we made every effort to use recyclable cushioning materials in our packaging.
Hashimoto: In these days of video streaming services, we see the growing popularity of Dolby Atmos, DTS:X, and other new formats that can reproduce cinema-like spatial sound in people's homes. Furthermore, as TV screens have become larger while the TV sets have become slimmer, there is less real estate in front of the screen. Sony has therefore taken on the challenge of developing a new product that makes it easy for anyone to create a full-scale cinematic environment in their own home. In 2021, we released the HT-A9 Home Theatre System, which makes it easy for anyone to set up and enjoy a complete, spatial sound system with just four wireless speakers and a compact main unit. It has been extremely well received, especially by film lovers.
Using Sony's original 360 Spatial Sound Mapping (360 SSM) technology, the HT-A9 was able to reproduce a spatial sound. Many users appreciated the sense of envelopment and seamless sound compared to other virtual surround sound technologies available on the market at the time. As the successor model to the HT-A9, the new BRAVIA Theatre Quad offers a further refined listening experience.
Hashimoto: We also considered how the HT-A9 would integrate into interior spaces, but with the BRAVIA Theatre Quad we leaned heavily into this idea and drastically changed the shape.
Deguchi: Sony's Creative Centre, which took the lead on the design, has continually thought about and proposed ideas on how a home cinema environment should be, given the changes in television environments—such as the increasing size of TV screens. If we were going to try to make the home cinema match with the big screen in the living room, then wouldn't it be ideal to make it flat and wall-mounted? It was with such questions in mind that we decided to make panel-shaped speakers for the BRAVIA Theatre Quad. From a technical standpoint, it is quite difficult to make flat speakers, but with this product, the development team was united from the beginning of the development process, working towards the design prototype with a strong sense of purpose.
Deguchi: Television sets in recent years have increasingly shaved down their outer edges, reducing them to a minimum so that when seen from directly in front, the image becomes almost the only thing one can see. It would probably be better if the speakers could be made invisible as well, but the fact is that they require a shape, so we have instead placed value on creating a pleasant presence.
Against this backdrop, we have established a design philosophy to apply to all our televisions and home cinema equipment that we call "Harmonic Presence", according to which products and spaces should have a pleasant presence and harmonise with each other to a high degree.
In line with this philosophy, we have given the BRAVIA Theatre Quad a simple, flat design that gives the impression that all surfaces are connected to each other, as a shape that symbolises the feeling of sound diffusing comfortably in a space, like light and scent. In addition, due to the product's characteristics, it will be placed in various locations and thus be viewed from various angles, so we aimed for a design that doesn't look out of place when viewed from any direction.
Deguchi: In addition to preventing the slimmed-down speakers from toppling over, we needed a bass-reflex duct underneath to boost the bass, and that is how we ended up with these stands that make the speakers look like they're floating. Incidentally, these stands can double as wall-mounting brackets as well.
Deguchi: Until now, with your standard home cinema system, if you wanted to mount your speakers on the wall, you had to purchase wall-mounting brackets separately, and after removing the stands, you still had to keep them in case you wanted to use them again in the future. Some people might have found it bothersome to store them somewhere, so they would have thrown them away, which has always bothered us from an environmental perspective.
And so, we have developed the stands of the BRAVIA Theatre Quad so that you can remove them and use a part of them as a wall-mounting bracket. We made use of the shape of the stand to make a bracket with a solid frame, which eliminates the impact of the wall or wallpaper texture on the quality of the sound. In addition, the brackets attach to two points at the bottom of the speakers, just like when we use them as stands. This means that regardless of whether you stand the speakers up or mount them on walls, they will always produce the best possible sound.
Nakamura: Finally, with this product not only did we address the speakers themselves. We also made an effort to reduce the plastic used in the packaging materials. One of the big changes was to swap out the polystyrene used to cushion and stabilise the product inside its box and replace it with a pulp mould made of recycled paper. We also took out the bands that hold the bundles of cables, replacing them with paper-based materials instead, reducing the amount of plastic used in small ways as well as big.
We generated a variety of ideas to reduce the environmental impact to a minimum, getting rid of the plastic bags for manuals and the shrink wrap on batteries, as well as making a little storage space in the cushioning materials so that the parts don't get scattered all over the place during transportation.
Abe: Going forwards, we intend to standardise the presentation for BRAVIA and other home cinema devices. Doing so would provide a smooth and seamless installation experience for customers who—to give an example—buy a TV and home cinema system together.
Ohshima: Once the initial settings have been applied, BRAVIA Connect also doubles as a substitute remote control, allowing you to operate basic controls and change detailed settings. It will also inform you about new functions and ways of using the system, so users will be able to learn more about the product through the app and discover new ways to enjoy it. And of course, if something goes wrong, they can also find troubleshooting information in the app.
Nakamura: 360 SSM is a unique piece of technology from Sony that combines distance measurement technology that detects the relative coordinates of the speakers and the distance between the speakers and the ceiling with a physical sound field reproduction technology called "monopole synthesis". It synthesises sound waves from multiple real speakers arranged around the viewer and reproduces realistic sound waves from so-called phantom speakers (i.e., virtual sound sources) at ideal positions for each content format.
Ohshima: Think about when a noise is emitted somewhere. You hear it when the vibrations in the air reach your ears, right? So that would mean that if you were to change the starting point of those sound waves, as long you could perfectly recreate the vibrations that reach your ears, then, theoretically speaking, you would perceive the sound as having come from that original location. We can apply this idea to sounds from films. The basic concept of 360 SSM is to work backwards and recreate the vibrations in the air when the sound is being played back in an ideal environment.
Nagahama: So-called virtual surround sound uses something called "psychoacoustic" technology, creating the illusion of a spatial sound to the listener. As a result, the effect varies from person to person, and there are limitations to the areas where the effect can be achieved. By contrast, 360 SSM technology actually generates a sound field, so anybody can get a solid feel for the sound, and the area where the effect can be achieved is considerably larger. People who never had a satisfying experience from virtual surround sound or those who want to enjoy a spatial sonic experience with the whole family should definitely experience the spatial sound of 360 SSM.
Nagahama: You will get the best results with content that supports spatial sound. With films, that would be content that supports Dolby Atmos or DTS:X, and with music, it would be content produced with 360 Reality Audio (360RA) etc. We would of course want viewers and listeners to listen to audio supporting those formats, but even content made with regular stereo audio, such as terrestrial digital broadcast television and YouTube videos, can be made to sound spatial when put through a 360 SSM system.
Nagahama: I think it would be good to test it out with something like a big budget action film, where you get intense sounds coming from above, behind, and all other directions. That would make it clear how much fun it is to watch a film with spatial sound.
Ohshima: Another standard approach would be to watch a live performance of music or theatre. That would also be well-suited to playing spatial sound. A sumo wrestling broadcast is surprisingly good for this sort of thing (laughs). If you watch it with spatial sound, you can get a realistic sense of the atmosphere around the ring as the sounds envelop you. With shouts from the crowd flying left and right, it will feel like you're physically there in the stadium. Of course, the same goes for broadcasts of other sporting events like baseball or football. Spatial sound is perfect for that sort of thing.
Nagahama: The lower the frequency of the sound, the larger the amplitude of the unit, so if you use the same unit to play back both the low range sounds like bass drums and basses and mid-to-high range sounds like human voices, then the human voices end up superimposed on the larger amplitude of the bass sounds, causing distortion. By going with a three-way configuration, we could play the low range and the mid-to-high range on separate units, reducing distortion and making the human voices cut through more clearly. I think this has made it much easier to hear the dialogue in films.
Hashimoto: It's also possible to add an optional subwoofer to increase the power of the low end. I highly recommend people give it a try.
Ohshima: The previous generation HT-A9 model also had a function that measured the relative positions of the four speakers and created an optimum sound field based on this information. This allowed users to enjoy a solid spatial sound even in cases where speakers could not be placed in the ideal positions. With the new BRAVIA Theatre Quad model, we have two new measuring functions.
Nagahama: To achieve this correction, we carried out tests in various environments and spent a considerable amount of time optimising the algorithm to ensure good results in any environment. Not only does this correction account for the room environment, but it also considers the installation conditions of the speakers. For example, if there is a wall near the speakers, sounds reflecting off the wall can adversely affect the sound quality, such as by causing voices to be muffled. The sound correction function fixes such issues. This is especially significant when using wall-mounted speakers. At the beginning of the interview, Deguchi said that users should mount the speakers on walls, and I agree. We have developed this product so that users can enjoy the sound quality even when the speakers are mounted on walls. This sound correction function makes it possible to provide the best sound with an attractive design.
Nagahama: The front speakers should be placed as symmetrically as possible for maximum performance. The rear speakers, however, can be placed asymmetrically, to a certain extent, and still produce a satisfactory effect through sound field correction. You can enjoy a firmly spatial sound, even if there are differences in height or orientation.
Tanaka: We emphasised the width of directionality when developing this system, and I think that is what makes it possible to achieve an adequate effect even if the speakers are positioned asymmetrically. The wide directionality maximises the effects of sound field correction.
Hashimoto: At long last, we can deliver the BRAVIA Theatre Quad, the much-anticipated successor to the wildly popular HT-A9, featuring improvements in sound quality, design and all other points. As I'm sure you gathered from our conversation, the BRAVIA Theatre Quad is the culmination of the unwavering efforts and strong convictions of the entire development team. We hope you have the chance to visit a Sony Store where you can test it out. We are sure you will be pleasantly surprised at the impressive sound produced by such a slim product.
Nakamura: As I mentioned at the beginning, this model has received the name BRAVIA Theatre Quad. That alone might tell you that we have placed great emphasis on developing a system that could be paired with BRAVIA. We hope that you will use this product together with BRAVIA at home and immerse yourself in a realistic sonic space like in the cinema, where picture and sound are one and the same.