Dolby and DTS are the two most widely used multi-channel audio formats in the industry today. These are two sound technologies that are present in a multitude of products, whether they are DVDs or Blu-ray, broadcasts through DTT, streaming videos on platforms such as Netflix and Amazon Prime, video games and much more. In this article we explain what exactly these two sound technologies are, as well as their differences and everything you need to know to get the most out of them.
What is Dolby and how does it work
First of all, we explain what Dolby Digital technology is . It is a multichannel sound system that is made up of 5 independent sound channels .
These five channels are front left and right, rear left and right, and front. Added to this is the subwoofer, which is responsible for providing the lowest sounds within the frequency spectrum.
Schematic of a multichannel audio system.
The LFE channel uses only a tenth of the bandwidth used by the rest of the channels, this is the reason why it is called channel .1, and that is why we speak of 5.1 audio.
Dolby Digital sound technology works using up to 24-bit 48 Khz original PCM source , which is exported to a compressed AC-3 file, which can achieve a maximum bit rate of 448kbps.
This means that it is a lossy audio format , which saves a lot of storage space and bandwidth, without significantly affecting the final quality of the audio.
Batman Returns was the first movie to use Dolby in 1992.
What is DTS and how does it work
We now explain what DTS technology is. It is another multichannel audio format that appeared in direct competition with Dolby.
In this case we find the exact same channel configuration as in the case of Dolby, so there is no difference between the two systems in this regard. The first movie to adopt DTS was Jurassic Park in 1993.
From here on, there are differences between both multichannel sound formats, since DTS technology works with an original PCM source at 48 Khz and up to 20 bits , which in this case is compressed to files with a bit rate that is understood between 768kbps and 1536kbps.
What is the most important difference between the two formats?
Dolby and DTS are two very similar multichannel audio formats, but there is a very important difference that is related to the compression of the data.
These are two audio systems with loss, although this is greater in the case of Dolby, since it achieves a significantly more aggressive compression than that carried out by its rival.
This greater compression of the data in the case of Dolby , is responsible for the fact that DTS technology offers superior sound quality. What is true about it?
The differences between the sound quality of both systems are very small , so appreciating it will be practically impossible, unless you have a very high-end sound system, and the user has a very tuned and trained ear.
The data compression system used by Dolby is more efficient, a key fact that allows it to offer a sound quality that is practically identical to that of its rival, while saving a lot of bandwidth and data size.
The latter is the main reason that Dolby technology is the most used in DVD and Blu-ray movies, as well as in streaming services such as Netflix and HBO, and in video games. Movie theaters also generally use Dolby technology.
For years there has been a fairly general trend, which is to use DTS technology for the main audio track on Blu-ray discs, while the rest of the audio tracks come in Dolby format to save space.
DTS is the most used technology in theme parks or virtual simulators, where space is not usually a very important problem.
What do I need to be able to use Dolby and DTS
Both Dolby and DTS require the presence of a decoder in order to be used. A decoder is nothing more than a device capable of receiving a signal in one format, and converting it to another format that can be used by another device.
Most of the televisions that we can find for sale today already include a decoder that is compatible with Dolby sound technology. In addition, all sound bars, AV receivers and home theater equipment also include Dolby decoders.
This is another very important advantage that the use of this technology has over DTS, since we will not have the need to purchase a separate decoder.
As for the decoders compatible with DTS technology, these are rarer to find included in the different devices that we can buy. They are being included in more and more devices, so this could change in the not too distant future.
Other interesting multichannel sound formats
Dolby and DTS multichannel sound technologies have not stopped evolving over the years with the addition of new technologies, and creating other standards that differ from the current ones.
The most important are:
- Dolby True HD : This is an 8-channel format without compression or loss of quality.
- DTS-HD : This is Dolby's competitor in lossless audio format. Supports up to 7.1 channels at 96 kHz and 24 bits with a maximum bit rate of 24.5 Mbit / s.
The best feature of these two new formats is that they are backward compatible with the previous ones. Those users who have a decoder compatible with Dolby or DTS, will also be able to use these new audio formats, although they will not be able to take advantage of their higher quality.