2015 introduced DTS (Digital Theater System), new audio format DTS: X . DTS was not the first to come up with a new format based on ‘3D audio objects like DTS Headphone: X. The company followed in the footsteps of Dolby, which came out with Dolby Atmos in 2014 .
DTS: X with Object-Based Sound
For the first time, these new formats do not contain audio based on speaker information, but based on objects. Object-based sound information is another new way to make sound sound more spacious. The information is encoded on the carrier with sound information such as objects and the playback device – for example the receiver – converts this into spatial sound. That means that in order to listen to Dolby Atmos or DTS: X, you must own a device that supports it.
Most AV receivers from 2017 support this and many receivers from 2015 and 2016 also. There are also all-in-one systems and sound bars that can decode Dolby Atmos and DTS: X. To be able to create a surround image from that object-based sound information, an AV receiver with calibration microphone can acoustically measure your living room. This allows the device to determine exactly where each speaker is located in the room.
Slowly, DTS: X is starting to break through, because more and more movies are available with this audio track. Dolby Atmos is slightly more available, on a larger number of films and even on films via Netflix . In addition to home cinema, object-based sound is also completely hot in the gaming world. This is often in a headphone variant, Dolby Atmos for Headphones or DTS Headphone: X.
Dolby Atmos can be used within Android and Windows, among others, after which you can listen to the format with any stereo headphones. Dolby Atmos only works if you play a game that offers Dolby Atmos, or if you watch a movie or series with Dolby Atmos. DTS Headphone: X offers a similar experience, except that the content must be (at least) DTS-HD and you must have software and hardware that support the correct decoding. In addition to laptops, smartphones and receivers, there are also headsets with DTS Headphone: X available. These are often headsets with a separate headphone amplifier module that contains the technology.
How does DTS Headphone: X work?
How is it possible that you experience spatial sound from simple stereo headphones? A lot of research has been done for this, not on the side of the transmitter, in this case a loudspeaker or headphones, but on the receiver, the human hearing.
Human hearing consists of two ears, so stereo. Because of the way in which sound reaches our ears, our brains ‘calculate’, as it were, where the sound comes from. If a sound comes from the front left, it will be loud and clear in the left ear, but the right ear will also receive something. This signal is much softer and also has a small phase difference.
By doing a lot of research into these aspects, it is possible to reverse this process. The use of ‘backwards processing’ makes it possible to adjust sounds in such a way that the human ear perceives them as spatial. This simple fact makes it possible to create surround sound without a surround source.
Currently, there are demos available where this reverse processing is used. These demos are ‘simple’ stereo recordings in a lower encoding quality, so you can listen to them on any device. So also on a smartphone of five years old with ears from the local supermarket.
Listening to these demos is impressive, but unfortunately it stays with demos. This gives you an image (or actually sound) of what is possible. This backwards processing is apparently so complicated that it is not done much with movies or music. Movies and music in DTS Headphone: X offer a more spacious sound than normal, but you do not get the feeling that there are speakers around you. For that we are still assigned to the demos.
DTS Headphone: X on Blu-ray
DTS Headphone: X is available as an audio track on some Blu-ray discs and Ultra HD Blu-ray discs. An audio track in DTS Headphone: X is basically a DTS HD track in stereo. The backwards processing has already been done in the studio for these tracks. This track is available as a separate track on the medium, in addition to often a ‘normal’ DTS X track. To be able to display the DTS Headphone: X-track, it is necessary that your equipment can handle DTS-HD. The audio track has been edited in the studio in such a way that the brain will think that the sound is all around it. So you don’t need a device that can specifically handle DTS Headphone: X.
The advantage of this setup is that everyone can basically enjoy DTS Headphone: X, as long as you have a device that can reproduce the DTS-HD audio format. It is already possible without an expensive receiver and with a dirt-cheap set of earphones. Of course, the effect is much better with good headphones, but this does give an idea about the accessibility.
Mobile devices and gaming headphones
Currently there are a few laptops, tablets and smartphones available with DTS Headphone: X. These devices can therefore reproduce a DTS Headphone: X stream and convert surround audio tracks to DTS Headphone: X. In addition to laptops, tablets and smartphones, there are also many gaming headphones with support available. These are provided with a small module that performs the decoding or conversion. The prerequisite is that the audio is present in a DTS HD bitstream and that the information about the placement of the sounds has been processed in the stream
So the technology is currently available for mobile devices and for gaming. There is still little new for home cinema applications, although several TVs from Samsung offer support for the format. These TVs can convert a multi-channel track to DTS Headphone: X, albeit limited to 5.1 channels.
As mentioned, AV receivers and other audio devices can deliver DTS Headphone: X, as long as they can handle the DTS-HD format. This only concerns media where a separate DTS Headphone: X track is present. At the moment there are no AV receivers that can convert DTS-HD (or another format) to DTS Headphone: X as soon as you connect headphones. For those who would like to permanently switch off their speakers and listen to all their films and music in surround via headphones from now on, it remains to be seen.