Gérard Loupias is the Director of Cinema and Content Development for the European continent at DTS. As an audio engineer, his career has notably included collaborations with Lucasfilm and THX. We asked him to tell us about DTS:X, an immersive audio format.
What is your role at DTS?
In addition to promotion and communication, my mission involves integrating DTS proprietary technology into all domains, including car audio systems, television, nomad devices, home theater installations, Blu-ray and Blu-ray 4K UHD, set-top boxes, VOD and Broadcast in France and in Europe. At the moment, I’m primarily working on bringing DTS:X to cinemas and Blu-ray discs.
What is the DTS:X audio format?
The DTS:X format is a version of MDA (Multi Dimensional Audio) developed for movie theaters and home theater installations. MDA is a PCM audio format which is based on objects and implements lossless compression. As a format designed for professional audio production, it is not publicly available. Sounds, audio tracks and objects are mixed together for a given number of audio channels to compose a 3D (immersive) or 2D (stereo, 5.1, 7.1) soundstage. They are then encoded in the lossless DTS:X format using the DTS-HD MA codec for Blu-ray discs and streamed or broadcast content. DTS:X uses metadata for each object based on three basic principles: when the object is played, at what volume, and where it is located in the sound field. During playback, rendering software takes into account the number and position of the extra drivers placed above the listener. The rendering software uses the metadata of each object to reproduce these audio objects at a precise time, volume and place within the sound field.
DTS:X is often associated with immersive sound: is it really better than typical surround formats?
DTS:X is a liberating tool enabling directors to create highly expressive movie soundtracks. DTS:X encourages innovation and offers a surprising, new audio experience which wasn’t hitherto possible. Immersive sound adds height and depth which 5.1 and 7.1 formats weren’t able to deliver. As such, it is a huge step forward in the world of sound.
What advantages does DTS:X have over competing formats such as Dolby Atmos and Auro 3D?
The main advantage of DTS:X is that it only takes one mix to ensure lossless playback absolutely anywhere. DTS:X has no limits when it comes to the number of objects, and it is compatible with IMAX, Dolby Atmos and Auro 3D speaker configurations (Editor’s note: this applies to both movie theaters and home cinema installations). In addition, DTS proposes a free license which allows European and independent film production teams to access the technology. Another advantage of DTS:X is its backwards compatibility with all DTS decoders installed since the Laserdisc! The smallest common denominator of DTS:X is DTS for 1.5 Mbps DVDs. DTS is the only company offering this level of audio quality to consumers.
How many speakers are necessary to equip or certify a DTS:X movie theater?
A 7.1 system is necessary, and our team verifies that there are enough surround speakers installed to fill the entire theater with sound by using a simple mathematical formula. We divide the width of the auditorium by 4. At one fourth of the width of the theater, there should be a 30° angle between two speakers. We repeat this on the sides and at the back of the theater before verifying the second row of speakers. Then we install one or two other rows of speakers on the ceiling, depending on the size of the theater. If the theater is already Atmos-enabled, we don’t change anything. The DTS:X format adapts to an existing immersive sound system without difficulty or loss in quality thanks to its advanced rendering software.
To what measure does sound come from speakers placed above the listener?
It all depends on the mix, as well as the location of the objects and their movements. It also varies depending on how immersive the film’s director wants the soundtrack to be. In practice, using more surround speakers requires an efficient acoustic treatment. If this isn’t the case, you’ll have the impression of being in a bathroom with a family having a political debate in another language! It’s a right mess!
How many films have been mixed for DTS:X screenings in movie theaters?
Over 150 films have been released in the DTS:X format, with over 20 such films released in July 2017 alone. Every day, the number is steadily increasing, and the format’s success is growing at a phenomenal rate.
How many movie theaters are presently equipped for DTS:X?
There are two ways to answer this question, either with the number of movie theaters which are operational or those which are in the process of becoming so. Over the course of the past 18 months, over 400 movie theaters around the world have become fully operational. Many more are currently being equipped or will be in the near future. We are very pleased by the demand from the movie industry for DTS:X. Most of our partners remember us for providing a great experience with 35 mm film (Editor’s note: DTS film), and there is shared excitement to build on this success.
How many Blu-ray movies offer DTS:X soundtracks?
A long list is available at DTS.com. More than 100 movies have been added in a short time. M6 video released La La Land in DTS:X in original and French dubbed versions, along with a DTS Headphone:X soundtrack for both versions.
Can you tell us about the DTS Headphone:X format?
The DTS Headphone:X format is a binaural version designed to let the user enjoy a 7.1.4 soundtrack, including audio objects, with a standard pair of stereo headphones. This allows those who don’t have a DTS:X decoder or extra vertical effects speakers to experience DTS:X. DTS produces this track using the original master recording, and the result is incredible.
Is the DTS:X audio track for Blu-ray different from the movie theater version?
In movie theaters, the DTS:X audio track uses PCM lossless compression. For Blu-ray and 4K Blu-ray, the audio track is in DTS-HD MA format and includes sound objects. Systematically, a new mix entitled “near field” or “home” is produced using the original Pro Tools session (Editor’s note: professional mixing software) in order to reduce the number of tracks to 7.1.4, which is the standard home theater format for Blu-ray–that is to say, 7.1 plus 4 channels dedicated to sound objects for the reproduction of vertical effects.
Due to their demands in terms of storage, DTS:X tracks are only available for Blu-ray and UHD Blu-ray discs. Is a VOD version in the works?
DTS:X exists in a special version for VOD. Its success will depend on whether there is demand for this experience. Operators are proposing it since it has become very easy to implement.
Which speakers are compatible with DTS:X?
For home theater installations, there are plenty of speakers to choose from. Surround speakers mounted on the wall or ceiling may be used to reproduce an immersive sound format.
How many speakers are required for a true DTS:X experience?
Ideally, 7 speakers are required for 7.1, plus a subwoofer and 4 ceiling speakers. This number also depends on the size of the room. (Editor’s note: A system composed of 7 speakers will get the job done).
May upward-firing speakers be used?
Yes, on the condition that the ceiling isn’t too high and doesn’t absorb the sound.
What is DTS Neural:X technology? Does it also involve using ceiling speakers?
Neural:X technology makes it possible to enjoy non-immersive content with an immersive speaker configuration. It relies on sophisticated post-processing techniques widely used for car audio systems, which are composed of many different speaker drivers.
Which movies would you recommend to someone looking to discover immersive audio formats?
It all depends on what you’re looking for, explosive sound or something more nuanced. Personally, I prefer having the impression of being immersed in a scene, at the heart of the action, rather than hearing sound effects. I like La La Land.
What is your favorite audio or cinematic memory?
Apocalypse Now with the analog soundtrack and 70 mm film at Kinopanorama, at the moment of its release. A great film, an amazing image, superb cinematography and incredible mixing. A simply breathtaking experience!