Dolby Digital vs DTS

Just like music, images, and videos, surround sound platforms are also available in several standards. However, the two most popular ones are Dolby Digital and DTS. Both Dolby Digital and DTS are supported by nearly all home audio systems nowadays. And there are many times when we are asked whether we want to play a film using Dolby Digital or DTS. But what is actually the difference between Dolby Digital and DTS? Is one really better than the other? Below, we will see the comparisons between Dolby Digital and DTS. Let’s start by knowing what Dolby Digital and DTS are actually.

Overview

Both Dolby Digital and DTS are surround sound codecs for 5.1, 6.1, and 7.1 home audio setups. If you are not very familiar with those numbers, know that the first number stands for the number of small ‘satellite’ surround speakers and the last one indicates a separate channel for a subwoofer. The most common setups are 5.1 and 7.1, whereas the 6.1 setup is very rare. There are also some setups that use two subwoofers, and these are usually called simply as 5.2 and 7.2 setups.

Both Dolby Digital and DTS are standards used by studios to compress dense files needed for the multi-channel audio and to decompress them in the receiver for playback. Both Dolby Digital and DTS are widely used in various applications and movies and TV shows that come via cable, satellite, DVD, or Blu-Ray.

Both Dolby Digital and DTS also provides multiple extra technologies, such as particular encoders for enhanced stereo, enhanced surround for extra immersion, conversion to match a non-standard number of speakers, etc. However, let’s just focus on the surround sound playback.

Both Dolby Digital and DTS formats use compression to save space. Space saving is needed for efficiency, which is needed to allow the studio to store large data in the DVD/Blu-Ray disc or to stream via cable or satellite. Some forms of both Dolby Digital and DTS are “lossy”, which means that there is a degree of audio degradation from the original source due to the compression. There are also “lossless” forms, which offer studio-level audio quality while still having some compression for space saving.

Quality Tiers

While Dolby Digital and DTS are heavy competitors to each other, they do use different technologies to achieve the same purpose: the most efficient compression with the least quality degradation. Dolby Digital believes that surround channels should be diffused, whereas DTS believes that surround channels should be directional. Each of them is available in several “tiers” of quality. So, it would be wise if we get to know their quality tiers first.

Dolby Digital

– Dolby Digital, for 5.1 systems with 640 kbps bitrate (common on DVDs)
– Dolby Digital Plus, for 7.1 systems with 1.7 Mbps bitrate (used by some streaming services, such as Netflix)
– Dolby TrueHD, for 7.1 systems with 18 Mbps bitrate (the lossless quality, available on Blu-ray)

DTS

– DTS Digital Surround, for 5.1 systems with 1.5 Mbps bitrate
– DTS-HD High Resolution, for 7.1 systems with 6 Mbps bitrate
– DTS-HD Master Audio, for 7.1 systems with 24.5 Mbps bitrate (the lossless quality)

The two standards are continually evolving, resulting in roughly comparable quality levels across their three tiers. There are also some other technologies, such as Dolby Atmos and DTS:X which offer alternative immersive modes for more distinct surround sounds, but the ones mentioned above are the standard applications.

Bitrates

At first, DTS may seem to have the advantage due to its higher bitrates across all the three tiers. However, we should note that we are dealing with proprietary technologies that use different techniques and methods. So, a higher bitrate does not always translate into a better audio quality.

By the way, the difference between the lossy and lossless tiers is also quite subjective, as there are some other factors that affect the quality besides the bitrate. The bitrate difference between the lossy and lossless tiers can be apparent on expensive, high-end speakers – assuming that your hearing is sensitive enough to discern the difference – but it is not very apparent on speakers of lower grades. In addition, your specific surround system may support either Dolby Digital or DTS better.

So, Dolby Digital or DTS?

Most surround systems nowadays already support both Dolby Digital and DTS standards, and these systems are also already smart enough to automatically use the default standard of whatever source that is currently being handled. If your home theater system does not incorporate audiophile-grade speakers, you will be fine with whichever default setting that is chosen. You will not notice any difference.

However, if you are assembling a new home theater system from sratch and you are ready to purchase those high-end receiver and speakers, you may want to be more detailed. Of course, most new receivers today already support both Dolby TrueHD and DTS-HD Master Audio. Some also come with Dolby Atmos or DTS:X. The latest Blue-ray releases usually stick to either Dolby Digital or DTS for their highest-resolution option, with more compressed options for the alternative language tracks. Hence, if you want to create the ultimate surround system, you should look for receivers, speakers, as well as discs or services that support the highest tiers of the Dolby Digital and DTS.

It is very rare that you get to choose between equivalent Dolby Digital and DTS tiers. However, if you do come across such instance, and you do not have any personal preference for either Dolby Digital or DTS, you can choose DTS for the higher bitrate. But, then again, you may not notice a very significant difference from Dolby Digital.

Dolby DigitalDTS
- Uses diffused surround channels- Uses directional surround channels
- Relatively lower bitrates- Relatively higher bitrates
- Slightly lower audio quality due to higher compression- Slightly higher audio quality

Conclusion

Dolby Digital and DTS are surround sound codecs for home theater setups. Dolby Digital uses diffused surround channels, whereas DTS uses directional surround channels. Both are available in several quality tiers, but the bitrates of DTS are higher than those of Dolby Digital. Still, the actual difference of audio quality between Dolby Digital and DTS may not be apparent.

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