Auro 3D Interview Continued
Audioholics: What kind of commercial support is Auro-3D seeing and how do you think that will expand in the coming years?
Wilfried: The power of our technology is full backwards compatibility. Not only are our speaker layouts based on the existing surround standards, but our technology allows us to integrate the Auro-3D master in the existing PCM standard, mandatory in each audio device. This solves a huge chicken-and-egg issue, which is always the problem with a new standard. There is already content that people have at home: hidden away in many Blu-ray discs are Auro-3D masters within the standard PCM. This concept makes the integration simple, and that is attractive for content makers since no extra investment is needed for the distribution. The same goes for the consumer who buys only one product while having two formats without any audible concession in each format.
Auro-3D's Auriga A/V receiver.
Audioholics: When do you foresee Auro-3D making its way into consumer products?
Wilfried: When we decided to bring Auro-3D out of the cinema and into the home, we were determined to get it right. We wanted to deliver true “Immersive Sound” to the consumer, to be the first, but also to be the best. I’m incredibly proud that we at Auro Technologies have done exactly that. A/V receivers and sound processors are ready and available for consumers to order. There are 3 Auro-3D branded sound processors and many A/V manufacturers will be launching Auro-3D integrated processors by the end of this year as well. The first car that will have Auro-3D integrated will be available to purchase at the end of 2015. The tools for game developers to create games with Auro-3D’s immersive sound are available as of now. Within the foreseeable future, Auro-3D will also be available on mobile platforms, delivering high resolution “Immersive Sound” by using just a single file, making Auro-3D the ultimate end-to-end solution to all markets
Audioholics: Is Auro-3D info encoded into a 5.1 PCM mix? If so, how much does this increase size? (Atmos results in an increase of about 20% over True HD from what folks are saying).
Wilfried: Exactly. The Auro-3D cinematic mix uses an artist-controlled dynamic down-mix (so no matrixing) of all channels into a 5.1 PCM carrier using the Auro-3D encoder plugin, resulting in identical file sizes relative to a standard 5.1 PCM mix. This 5.1 PCM carrier sounds the exact same as if the same mix would have been done on a top digital console. Following our workflow, the Auro-3D mix and the 5.1 surround mix are both created at the same time without any compromises in the artistic intent of each format, and without any extra time needed than normally used for the 5.1 surround mix only. So this ‘single file’ master carrying both formats is going into the professional and consumer market as a 24 bit PCM stream (uncompressed audio) which can be put on each standard Blu-Ray or DCP (Digital Cinema Package). If a standard cinema server has our Auro-3D Decoder (just a software upgrade), it recognizes the metadata immediately and will automatically decode the signal into the original Auro-3D mix. The cinemas that don’t have the Auro-3D Decoder will hear the standard 5.1 PCM uncompressed audio.
The concept for home cinema is similar. All existing Blu-Ray players will play back the 5.1 Auro-encoded stream as a normal 5.1 surround mix, but A/V Receivers which have the Auro-3D Decoder and speaker layout will detect the Auro-3D mix. Due to our groundbreaking technology, we don’t need any change in specs or new delivery formats, nor extra bandwidth to bring an immersive audio experience with studio quality into the professional cinemas or to the consumers at home or on their mobile platforms.
Audioholics: Just to confirm, you’re saying that Auro-3D is fully compatible with Blu-ray?
Wilfried: Yes, Auro-3D is 100% compatible with the existing Blu-Ray standard. We use PCM uncompressed audio tracks (up to 8 tracks), and due to our groundbreaking Auro-Codec, we are able to add up to 16 additional tracks (24 in total) of high resolution audio. It does not even matter which HMDI version you’re running because the 8 PCM channels in Blu-Ray were already part of the spec from the beginning. This 100% backwards compatibility allowing us to carry multiple high resolution mixes is an important advantage of the Auro-3D format and allows easy integration in all markets.
Audioholics: How many channels of audio are possible with Auro-3D in the Cinema and the Home? The Auro-3D PDF mentions up through Auro 11.1, though it looks to be based on a 5.1 with 5 height channels and one top channel. We’re guessing it could go up to Auro 13.1 with a 7.1 base setup?
Wilfried: That’s correct. But it doesn’t stop with Auro 13.1 because above that number, we can use object-based technology to add more point sources on the 3-layered system. The question is how many people will install at least 20 speakers at home in order to have more precise localization of sounds for some flying objects? We don’t feel that a higher number of speakers automatically translates into a more immersive experience or improved sound reproduction. It is rather the opposite: each extra channel results in extra phase issues. The art is to create the most immersive experience with the minimum amount of channels related to the size of a room, and that is what we achieve with the Auro-3D format.
Auro's CEDIA demo included an impressive 20.1 setup.
Audioholics: Is the Auro-3D addition effectively lossy encoded discrete channels rolled into the PCM mix, or an object mix like Atmos?
Wilfried: Auro-3D technology preserves high-resolution audio for each channel, not only in the down-mixed master but also in each decoded channel. The concept is very simple. The dynamic resolution of 24-bit equals a dynamic range for more than 140dB, which means that on top of an extremely quiet background noise of 20 dB, you can achieve sound pressure levels (SPL) up to 160 dB… blood will come out of our ears. In fact, you can hear 24-bit only once in your life because if you have experienced it, you are just completely deaf. Additionally, there are no Digital to Analog convertors or amplifiers that can give this dynamic range.
So why do we use 24-bit? This is needed during the workflow for different technical reasons, but the moment we come to a delivery format, a dynamic range of 105 dB is more than enough, meaning peaks up to 125 dB SPL on reference listening position. Every bit equals 6dB of dynamic range. This means that an 18 bit lossless quality is the maximum we need as delivery format, confirmed by Tomlinson Holman (THX) at ICTS in 2012. The Auro-3D codec uses the 4 least significant bits (a noise floor you can’t hear) to put some metadata in, which allows us to reproduce each channel in high resolution quality.
In case of using object-based technology like Atmos, it is inevitable that much more bandwidth is needed if all objects have to be reproduced in a lossless audio quality. It’s unclear how Dolby could deliver 128 objects losslessly in a Dolby True HD stream on the existing Blu-Ray format! The only way to have so many objects in the bandwidth available on Blu-Ray is to use a lossy compression scheme ... and therefore they could use AC4 which is the AC3 codec expanded with object based capabilities.
Even Dolby True HD is not 100% lossless... when sounds become very dense with many high frequencies, I know that MLP is not able to do that within that bandwidth. We already heard in our mastering room a difference between Dolby True HD decoded version and the original. This is not the case with DTS Master HD which is 100% lossless and creates the exact same bitstream as the original.
We all know that lossy audio codecs like MP3, AC3 or AC4 are causing distortion to the signal and are eliminating spatial information. Additionally, it has been proven that this subconsciously creates fatigue to the listener. I wonder how many people are going to install an immersive system with so many speakers to finally listen to a lossy audio quality? I prefer to go for the more relaxing experience of Hi Res Audio in each channel and no funny things due to too much freedom in speaker layouts. I believe that the scalability of speakers setup for home (Auro 8.0 up to Auro 13.1) is more than enough and will give the consumer an experience which is much closer to the original studio version as intended by its creators, being it movies, films or broadcasting of live events.
Audioholics: Looks like the speakers are located in the traditional “height” spots (excluding the 10.1 and 11.1 which use center height and top channels). Is this correct?
Wilfried: The Auro-3D speaker layouts are designed with a hierarchy in mind, meaning that we start with Auro 8.0 as the most efficient true 3D audio system. In order to achieve full backwards compatibility, we advise consumers at home to choose the Auro 9.1 system. Of course, for fly-overs and special effects, the addition of an overhead ceiling speaker (Auro 10.1) makes sense, but as already stated before, it is not necessary in smaller theaters. This third layer is treated as a mono channel in order to create the best scalability and largest sweet spot. In combination with the Height layer, this creates a very wide stereo field.
The height center speaker in the front (Auro 11.1 system) is needed in professional cinema theaters and is recommended for people who have a large screen at home. For very large home cinema theaters with at least 2 rows of seats, we suggest the Auro 13.1 system, which delivers the most immersive sound reproduction with the best audio quality and enough speakers to also make good use of object-based technology.
Auro-3D adds height channels over the existing 5.1/7.1 formats, and offers the option for "Voice of God" channels as well to complete their dome of sound.
Audioholics: Will Auro-3D allow for non-rigid speaker placements and be able to detect where the speakers are located in the room in order to adopt to the layout?
Wilfried: Our speaker layout already has a tolerance which we believe is big enough to install an Auro-3D system within our specs everywhere. More than 350 systems are already installed within the specs without the need for reconstruction. The deviation beyond our tolerances will always lead to less compatibility with the creative intent, even when using object-based technology. It all sounds great that technology is able to recalculate poor placements of speakers, but consumers should be very careful with these kinds of marketing claims. The tolerances to do that kind of mapping properly are much smaller than people would believe, even with the use of object-based technology.
Audioholics: Will Auro-3D offer an option like Atmos Elevation speakers to bounce sound off the ceiling or do you find that method to not be an effective solution?
Wilfried: First of all, to create the most immersive sound, you don’t need sound from the ceilings but a vertical stereo field in front, sides and behind the listener between ear-level and a height of about 30°. The sound bouncing off the ceiling can never create the same quality of sound reproduction. Of course we looked into that as well, but we don’t like to make false promises. This doesn’t mean the effect won’t work, but it is not comparable with the real thing.
Elevated sounds cannot be created as vertical phantom sources without the use of psycho-acoustic effects like those used in the horizontal plane by using ‘sound bars.’ The quality of sound bars in the horizontal plane is not comparable with a 5.1 or 7.1 speaker system, and it will be even worse using that technology for the reproduction of height. The use of such psychoacoustic effects (like notch filters) will always have a bad influence on the original sound quality of those height channels. The modes of the low to mid frequencies down to less than 300 Hz are key for our brain in spatial sound processing. The material of the ceiling has to reflect all those frequencies in the same way, as if the sound were coming from a height speaker. That is impossible. For that reason, above the ear-level layer we use a Height layer with speakers around the listener to enable the reproduction of the elevated source sounds as well as the most important native true 3D reflections around those source sounds.
Auro-3D supports various speaker layouts for the home, ranging from their Auro 9.1 setup for most home installations, up to Auro 13.1 for larger home cinemas. Auro 9.1 is based on a standard 5.1 Surround setup for the lower layer, augmented with four height speakers, sometimes referred to as the quadrophonic sky, positioned at 30º above the front left and right speakers. This setup is considered to be the minimum setup for real “Immersive Sound”, with a level of realism that can barely be surpassed by any other system given that the majority of the immersive effect is created by the interplay of the lower and height layers. From Auro 10.1 onwards, the speaker setups also have the third layer on the ceiling, to complete the ‘dome of sound’ all around the listener. This top channel is then mostly used for special effects such as fly-overs, similar to what happens in reality. The well-defined and fully compatible speaker layouts of the Auro-3D format for cinema and home guarantees the same immersive sound experience as it was originally intended by its creators.
Auro will NOT support Dolby's Atmos-enabled speakers, such as Pioneer's new Elite loudspeaker lineup.
Audioholics: Is there one unified speaker layout that would be compatible with Auro, Atmos and DTS UHD? If so, how many speakers would that involve and in what layout scheme?
Wilfried: In order to maintain cross-platform compatibility, we would suggest the Auro 9.1 which is 5.1 bottom + four Height speakers located 30° above the ear-level front speakers. This is close to the 5.1.4 format from Dolby, with the difference being that the angle to the listening position of the ceiling speakers will be closer to around 50° to 60°. This is a significant difference, and Auro-3D native productions could sound funny because reflections and source sounds mixed on 30° elevation for the Height channels won’t sound quite right being reproduced at around 50 to 60°. But if people install the Auro-3D speaker layout, they can playback Auro-3D content properly and due to Dolby's and DTS's claim that their object-based technology allows them a wide range of speaker layouts, an Auro 9.1 layout should provide good results there as well.
The Auro 9.1 layout seen above should allow cross compatibility with the Atmos 5.1.4 layout.
Audioholics: What are the interactive possibilities with object-based technology for consumers?
Wilfried: The most important interactive possibilities can be integrated in the metadata of the Auro-3D encoded stream. We don’t need to go for object-based technology to cover most of those options. Too much freedom is not a good thing. I remember when they offered multiple video streams for movies so people could select different camera positions in Europe. Everybody thought it would make a big difference but it failed completely because after people tried it out a few times, they just switched back to the main program again. We should not overblow the need of such options and make the consumer invest in things they don’t really need. Being immersed by a high quality, true 3D system at home will make people happy, while allowing them to enjoy all of their favorite music and film content in a new way. Bringing that final dimension in the evolution of sound to the world seemed to be my mission. Seeing this happening now makes me very happy.
Audioholics: What Auro 3D titles are currently available on Blu-ray?
Wilfried: The list of titles currently available are:
- Trondheim Solistene - Souvenir (http://www.2l.no/pages/album/090.html)
- Remote Galaxy by Flint Juventino Beppe (http://www.2l.no/pages/album/100.html)
- Mando Diao - Aelita (http://www.mandodiao.com/official-media)
- Lichtmond 3 (to be released Oct 10th - http://lichtmond.com/index_en.php)
- Crossover Experience Volume 1 (http://www.sa-cd.net/showtitle/9816)
and we are currently working on many more to come (soon to be announced)
Audioholics: Will Auro-3D support streaming services via DVR’s and STB’s?
Wilfried: We are working on the streaming side of things and we are sure this will be available in the future. As of now, Blu-Rays are the way to go for now (either via decoding or upmixing with the Auro-Matic).
That's a Wrap!
We would like to thank Wilfried for the time he took to give us an inside look at the Auro-3D format. We were able to demo an Auro-3D system built around a Datasat processor and James Loudspeakers at CEDIA 2014. To say we were impressed would be an understatement. It was in fact the best sounding multi-channel surround demo we heard at the show (though to be fair, we didn't catch the JBL demo which received high marks from others). The sense of scale and ambiance added by the height information is nothing short of breathtaking. We can't wait for more Auro-3D products to start hitting the market so we can test them in our own listening environment.
For more information, visit the Auro-3D Official Website
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