The X Dimension – Q&A with Paul McCambridge

Paul lives and works out of his home in Toulouse, that he shares with his wife, two small children and a small beagle pup. In between changing nappies and battling sleep deprivation, you can find Paul swimming in the lakes, cycling up the mountains, and running through the countryside of the south west of France.

In this Q&A, we discuss the history of DTS, immersive audio and its evolution to DTS-X as well as its latest applications.

Paul, please give us an outline of your background and your involvement with DTS.

I am a technophile at heart passionate about creating extraordinary experiences. Over the last 18 years I have worked in various roles spanning software development, technical account management, field applications engineering and now sales. I am currently working at Xperi (the mothership of the DTS audio brand), helping partners to make entertainment more entertaining, and smart devices smarter through our rich portfolio of audio products.

I live and work out of my home in Toulouse, France, that I share with my wife and two small children. In between changing nappies and battling sleep deprivation, you can find me swimming in the lakes, cycling up the mountains, and running through the countryside of the south west of France.

Why DTS? How would you explain the difference to audiences between Dolby Digital & DTS? What’s unique or so special about it?

Both formats fundamentally set out to achieve the same goal of delivering fantastic surround sound experiences. The methods employed in achieving that goal vary. To understand the differences, you need to look back at the history of DTS.

In 1993, Jurassic Park was released in movie theatres with visual fx unlike anything audiences had ever seen. Integral to magic of that movie was the sound, and the director, Steven Spielberg, knew that the accompanying audio technology needed to shine as much as the visuals. DTS was enlisted to bring digital multi-channel audio to movie theatres and the results were exceptional. That event put the relatively unknown DTS into the spotlight and jumpstarted decades of leading audio technologies.

In 1997, DTS became available to home cinema aficionados in the form of DTS Digital Surround. Available on DVD and select LaserDiscs at the time, DTS Digital Surround enabled high-performance home-theater audio and received rave reviews given its higher-bit-rate audio (i.e. less compressed than competing formats) and resulting dynamics.

In 2005, Blu-ray disc players hit the market bringing high-definition video and lossless audio to consumers. DTS was written into the Blu-ray Disc Association’s spec as a compulsory audio track and DTS-HD Master Audio was born. With up to 8 channels of lossless audio, DTS-HD Master Audio took home theatre systems to the next level. At this stage the compression gap widened when compared to competing HD formats. Dolby Digital Plus supports up to 1.7Mbps, while DTS-HD High Resolution supports up to 6Mb/s. In theory, less compression during encoding equals more detailed audio that delivers a soundtrack closer to what was originally intended.

Some years later, in 2015, DTS:X was launched, bringing our next-generation immersive audio technology to market. With the ability to deliver audio to speakers placed around and above the listener in a room, DTS:X delivered our most enveloping audio experience to date. And with the recent release of our DTS:X Pro decoder package, consumers can now enjoy up to 30.2 channels of output.

It would be remis to say that one format is better than the other, both are providing two “flavours” of Surround Sound and Immersive Audio, and audiophiles may have their own preference based on personal taste. What is important is that there is a choice of formats for the consumer and that the competition between Dolby, DTS and other emerging formats continues to drive innovation in the cinema and home entertainment space.

DTS at home – how do studios choose DTS for audio tracks? Do they approach you or vice-versa?

The process is more organic, there are over 100 DTS:X capable mixing facilities worldwide including iconic names such as Skywalker Sound, Abbey Studios, and Sony Pictures.

Producing movie soundtracks is a merciless business, and sound engineers are subject to increasing time pressures. In some cases, they may have as little as a weekend to produce a cinema-ready mix. With mixing facilities concentrating on cost and speed, more than ever, being able to drop something in and produce a publishable mix quickly is of upmost importance. The advent of object-based audio has gone some way to simplifying the process.

One of the most attractive features of DTS:X to the studios is that it simultaneously deliveries fully immersive cinematic audio at the same time as providing cost savings. We have had feedback from mixing studios that suggests that it takes less time to produce a DTS:X mix compared to the alternatives. The implementation is also simpler, as it only involves a plug-in to the most popular mixing software, Pro Tools.

What is DTS:X and DTS:X Pro?

DTS:X is our next generation immersive audio codec, that builds upon decades of surround sound audio encoding know-how.

So, what is Immersive audio I hear you ask? Well it is any creation or playback environment that includes the presence of audio above the listener. In a home theater system, for example, this might include dedicated height speakers, up-firing speakers for sound reflection, or perhaps virtualization whereby psychoacoustic principals are leveraged to give the listener the perception of sound coming from above and behind them. You’ll hear the term “immersive” used often. When we use it, we intend to describe an environment wherein the listener is completely enveloped by the soundscape.

You will probably also have heard the term “object-based audio” or “audio objects.” An audio “object” is an audio element with associated metadata that defines how it is rendered in the listening environment. Sound is no longer confined to a specific location in the mix (the LEFT speaker, for example). Instead, the content creator can assign audio to an object that is then manipulated in space, encoded to the DTS bitstream, and then recreated accurately in the consumers’ home utilizing his or her specific speaker setup. The DTS:X decoder solution for consumer devices combines these two elements: immersive audio and object-based audio to bring that big screen experience to the home. With the increased spatial resolution provided by the height channels, consumers now enjoy their favourite content with sound in front of, beside, above and behind. DTS:X delivers the most true-to-life audio experience in the home we’ve ever created.

Our DTS:X decoder solution also includes a technology known as Neural:X. Neural:X is an up-mixer and spatial remapping engine that ensures sound is optimized for the consumers’ specific speaker layout. Whether the end user has a few speakers in the living room or a custom theatre, Neural:X ensures the source material is appropriately distributed to all connected speakers in the listening space. Regardless of where it originated, Neural:X accepts PCM audio – be it stereo, 5.1, 7.1 or more – and up- mixes the content to all connected speakers.

When we developed the technology, we architected it such that there was theoretically no limit to the number of channels or objects that we could supported. In practical terms however, there were physical limits (processing power, memory, complexity of testing an infinite number of speaker configurations etc.) which meant that the supported channel layout was limited to a maximum of 7.1.4.

Over time we have been asked by our partners in the high-end cinema space to remove some of these limitations and provide support for up to 32 channels of audio. That led us to release a codec extension called DTS:X Pro which, on certain high-end chipsets and architectures, provides the ability to extend the functional range of DTS:X to cover high channel count home cinema installations. It is important to note that DTS:X Pro is not a format, it is an extended version of DTS:X that works seamlessly with all existing versions of DTS.

With DTS:X Pro, we also introduced an updated version of Neural:X that now supports up to 30.2 output channels. Particularly unique is the fact that Neural:X up-mixes the bed to all active outputs while working hand-in-hand with an updated object renderer to precisely position audio objects in space.

Neural:X also delivers value to those who have a collection of older audio technologies. A consumer’s aging DVD collection, for example, featuring our original DTS Digital Surround technology, can be decoded by DTS:X, passed to Neural:X, and up-mixed so that every speaker in the room is utilized. This is made possible by our “core + extensions” approach to codec engineering.

Where can we find content encoded in DTS:X?

There are two primary sources of DTS:X content: 4K Ultra HD Blu-ray disc and streaming. In Europe you can get DTS encoded content along with IMAX Enhanced quality imagery via Rakuten TV in Europe. Sony recently announced their Bravia Core super high but rate streaming services that promises to deliver audio and video on par with 4K UHD Blu-ray, again this service will carry IMAX Enhanced and DTS encoded titles. Furthermore, you can expect some very exciting news early this year on another major milestone for DTS audio.

Tell us more about IMAX Enhanced

The IMAX Enhanced program is particularly interesting as it includes unique versions of blockbuster titles, digitally remastered by IMAX for home release with audio delivered exclusively by DTS. The project has gained significant momentum this past year and is proving to deliver amazing experiences to consumers in their homes.

It is a collaborative project between IMAX and DTS that aims to address two main challenges:

1. Device differentiation: helping consumers to identify best in class products

2. Optimised viewing: Creating a premium playback experience that remains faithful to the filmmaker’s creative intent

To achieve this goal the program combines digitally remastered 4K HDR content and DTS audio technologies with best-in-class consumer electronics products and streaming platforms.

From and image standpoint, IMAX Enhanced content boasts ultra-vivid 4K HDR picture that has been treated by IMAX’s proprietary digital remastering technology (DMR). Thanks to IMAX movies being shot with cameras capable of capturing tall aspect ratios, select IMAX Enhanced content features an exclusive expanded aspect ratio – removing letterboxing and displaying the movie in the way it was intended.

Sound-wise, DTS audio technologies are used to deliver the IMAX immersive signature sound. In an IMAX cinema, the audio presentation is more like a home audio setup than is a traditional movie theatre system. IMAX cinemas employ a point source mix to deliver 12, 6 or 5 discrete audio channels, depending on the movie. Blockbuster titles, for example, are more likely to utilize a 12.0 mix. The 12.0 speaker layout in an IMAX cinema is very similar to an 11.1 layout in the consumer’s home. We have worked along with IMAX to translate the 12.0 IMAX cinema mix to the home utilizing a DTS:X bitstream featuring an 11.1 speaker layout with a centre-front-height object positioned above the screen. When played back on a consumer’s 11.1 DTS:X system, that centre-front-height object is rendered to the appropriate location utilizing the speakers that are available.

The intersection of IMAX Enhanced and DTS:X Pro is exciting. In an 11.2.9 DTS:X Pro speaker setup, for example, the centre-front-height object is positioned precisely in the speaker that has been connected to that output channel on the IMAX Enhanced A/V receiver or processor. In such a setup, the consumer has effectively replicated the IMAX cinema speaker layout and receives an impressively accurate presentation of the original audio mix. You’ll notice in the accompanying image, however, that a number of the consumer’s speaker are unused when playing back IMAX Enhanced content while Neural:X is OFF (also known as Direct Mode). This is ideally suited for the audio purist, but many people want all speakers active at all times.

The program currently boasts a large number of partners in the audio in video space, featuring some of the world’s most well-known brands such as: Sony, Philips, Hisense, TCL, Polk, JBL, Onkyo, Denon, Marantz, Trinnov, Arcam etc.

As the program continues to gather pace we will have lots of news to share with you in 2021!

You can stay up to date by checking out imaxenhanced.com