Both Dolby Digital and DTS are great encoding and decoding consumer technologies. However, DTS is encoded at a high bit rate, and thus decoding is more mathematically accurate than in Dolby Digital. On the other hand, Dolby claims to have better decoding.

With that said, most typical home theater users cannot pick up the sonic differences between the two modes as they are similar in many ways but differ in others.

If you can hear subtle audio details (most of us can’t), you may easily conclude that DTS offers better sound quality than Dolby. However, you can’t directly compare these two technologies as each has different subsets that fall under it.

It would make sense to compare between closely similar subsets to tell which is better. An example of this would be comparing DTS-X with Dolby Atmos.

However, before we can look at each of these sound processing modes, it would be worth briefly learning about audio encoding and decoding.

What is encoding and decoding?

Encoding is the process by which analog sound waves are sampled and stored in a DVD, CD, Blu-ray, online files, and so on while decoding is the process by which the encoded data is processed and split into various channels a stereo or surround sound system.

Audio encoding is usually using pulse-code modulation or PCM where the sound is sampled and compressed into digital bits of 1s and 0s. These 1s and 0s are then converted into an electrical signal after decoding and amplified to produce sound.

How encoding and decoding is done in DTS and Dolby Digital

DTS and Dolby encode and decode their audio files at different bit rates but both Dolby and DTS have to compress their audio files during encoding for space efficiency.

However, the compression in DTS is 3 times less than that in DD. This is because DTS uses a bit rate of 1.5 megabits per second with the sampling rates going as low as 768 kilobits per second in DVDs.

Dolby Digital, on the other hand, compresses surround sound files at 640 kilobits per second which can go to as low as 448 kilobits per second.

This is a huge gap as far as sampling rates are concerned and it even widens once you get into the specific modes such as 6.0 megabits per second for DTS-HD and 1.7 megabits per second in Dolby Digital Plus which are two very similar formats.

However, Dolby claims to have better and more effective decoding speeds than DTS, a claim that has been echoed by other experts in the surround sound industry.

This means that DD can compensate for the differences in codec details with faster processing speeds but the bit information stored by DTS is too large to compensate with decoding. The more data a sound processor has to work with, the better the decoded information and sound-quality will be.

But by my experience, you need a very high-quality sound system to hear differences between the two codecs and processing modes. It all comes down to your preference and how well you can notice subtle nuances in the sound quality by both.

Dolby Digital explained

Dolby Digital is also known as a DD or AC-3 is a lossy surround sound compression codec brought to us by Dolby Labs and was first used in 1992 in the movie Batman Returns.

This codec is made up of 6 discrete channels that include 5 surround channels and one LFE channel for the Low-Frequency Effects to create an immersive sound. The 5 surround channels include 3 front channels (left, right, and center channels) and 2 surround channels (left and right surrounds).

For a receiver or any other sound processor to decode DD codecs, it needs to have the processing mode capable of decoding it to create an electrical sound signal. The source should also be encoded using this technology before the data is sent to the processor using a coaxial/optical or HDMI connection.

However, DD digital soundtracks can also come in stereo 2.0 channel formats that can be used in a stereo sound system.

Dolby has also expanded on the Dolby digital codec to create more advanced codecs such as Dolby Digital Plus, Dolby Digital EX, Dolby Pro Logic II, Dolby Pro Logic IIx, Dolby Pro Logic IIz, Dolby TrueHD, Dolby Atmos, Dolby Surround, and Dolby Atmos Height Virtualization.

1.      Dolby Digital Plus

Dolby Digital Plus, DD+, or E-AC-3 is an enhanced 5.1 surround sound codec that allows you to reach up to 16 channels but is usually used in a 7.1 setup.

2.      Dolby Digital EX

Dolby Digital EX expands on the DD technology for a 7 channel (6.1 channel) system.

6.1 home theater systems are not common but if you use this mode on your AV receiver and have an extra speaker for that channel, Dolby Digital EX should be great. However, if you choose this mode but with no extra speaker, the receiver will autoplay 5.1 channels.

3.      Dolby Pro Logic II

Dolby Pro Logic II also known as PLII is a Dolby processing mode that creates a 5.1 channel signal from a stereo codec.

This means that you can enjoy a virtual 5.1 surround sound effect from a stereo source but can also work with a 4-channel Dolby source. It may not be as good as a true 5.1 source but it should do the trick.

4.      Dolby Pro Logic IIx

Dolby Pro Logic IIx or PLIIx is a Dolby surround sound processing mode that up-mixes a 2 channel of 5.1 channel signal to create a 6.1 or 7.1 surround channel effect.

This will depend on whether you have the extra speakers in your home theater set up.

5.      Dolby Pro Logic IIz

Dolby Pro Logic IIz or PLIIz is an enhanced version of Pro Logic IIx processing mode that expands a 5.1 or 7.1 source for a 7.1.2 or 9.1 playback.

To expand to 7.1.2, you will need to have 2 additional height speakers, 2 ceiling speakers, or 2 up-firing speakers. This means that your receiver should have 2 extra channels for this Dolby processing mode to work.

6.      Dolby TrueHD

Dolby TrueHD is a lossless 5.1 surround sound codec that can be detected directly by your AV receiver after transmission if you have not selected the decoding mode. This is a large-sized file that is mainly stored in Blu-ray disks.

However, not all receivers can decode this codec but if your source such as Blu-ray has a decoder for a Dolby TrueHD file, you should be able to play the file by bypassing the processor on your receiver.

To bypass the processing on your receiver, you will need to set the Blu-ray player or gaming console (Xbox and PS4 can be used to play Blu-rays) to LPCM (Linear Pulse-Code Modulation).

Dolby TrueHD is better than Dolby Digital as it is stored in a lossless format and has more information for the sound processor to work with and create a hi-res immersive surround sound with a better dynamic range in your home theater system.

7.      Dolby Atmos

Dolby Atmos is a lossless object-based 3D surround sound codec and processing mode. It is an extension of Dolby TrueHD that adds an extra height element to create a bubble around the home theater user.

It is mainly used in a 5.1.2, 5.1.4, or 7.1.4 channel system but can be used in a home theater that has up to 35 powered channels.

Having such a system, a Dolby Atmos source, and a Dolby Atmos processor, will enable you to have an immersive 3D surround sound experience. The sound effects will make you feel like you are interacting with the environment similar to what you are watching, whether is an overhead chopper, flying bullets, birds, leaves falling, and so on.

However, you cannot experience Dolby Atmos if you do not have height speakers, ceiling speakers, or even up-firing speakers that bounce soundwaves off your ceiling.

8.      Dolby Surround

Dolby surround is a sound processing algorithm that works with a system tailored for a Dolby Atmos surround sound but without needing Dolby Atmos content.

This means that it can up-mix a standard 5.1 or 7.1 audio file and add extra height channels depending on the number of heights, up-firing, or ceiling speakers that you have and how you have allocated them in your home theater processor.

Dolby Surround can also work with stereo content and up-mix for surround sound and allocate sound signals to the various speakers that you have in your set up.

9.      Dolby Atmos Height Virtualization

Dolby Atmos Height Virtualization is a Dolby surround sound processing mode that aims to create a virtual 3D Dolby Atmos effect without needed height or in-ceiling speakers.

This will save you from the hassle of having to fit speakers in your ceiling or buying up-firing speakers that do not always work great in all home theater rooms. However, you will need a receiver, preamp, or processor that can support this mode and can be used in a 5.1 or 7.1 set up.

The processor is fitted with height-cue filters that can emulate that immersive bubble effect with your current surround sound system.

If you have a receiver, you can contact your manufacturer to confirm if they have a firmware update for this virtual processing mode and try it out. However, if you already have speakers for your height channel, this will not be necessary.

DTS explained

DTS stands for Digital Theater Systems and was the name used before it was changed to its abbreviation, DTS. It is a direct competitor to Dolby Labs but was founded later on in 1993 after Dolby had been in the industry for some years.

DTS technology made a major milestone after it was used in the movie Jurassic Park which propelled the company to popularity.

This sound technology also uses lossy compression but is sampled at a higher bit rate than Dolby Digital and is also more adaptable to different rooms and home theater systems.

This is because DTS uses software that can analyze the speaker system, tune changes in different ways, and can optimize bass depending on your system and subwoofer. Let us take a subwoofer, for example, DTS analyzes the capabilities of the sub-drivers and if it can’t play a certain frequency well, it makes it softer for the driver.

But just like DD, DTS has developed different codecs and processing modes that can be used in a home theater or media room. They include DTS-ES, DTS Neo:6, DTS-HD Master Audio, DTS-X, DTS-X Pro, DTS Neural-X, and DTS Virtual:X.

1.      DTS-ES

DTS-ES, also known as a DTS Extended Surround, is a processing mode that adds an extra channel to a 5.1 channel surround sound set up.

This decoding mode can come in either DTS-ES 6.1 Discrete or DTS ES-Matrix. DTS-ES 6.1 Discrete processes a DTS-ES soundtrack and adds one or two rear channels to create a 6.1 or 7.1 surround sound while DTS ES Matrix adds a matrixed center-surround channel.

2.      DTS Neo:6

DTS Neo:6 is a DTS decoding mode that up-mixes a stereo 2-channel audio file and distributes it to 6 channels for a 5.1 or 6.1 surround sound. This mode is similar to PLII/PLIIx.

DTS Neo:6 comes in two versions where one is optimized for music listeners and the other for watching movies in Music and Cinema respectively.

3.      DTS-HD Master Audio

DTS-HD Master Audio is a lossless codec and decoding mode that can be found in some sound processors and soundtracks.

When playing a DTS-HD soundtrack, your receiver/pre/pro will switch to this mode if it is available after it detects the signal to an unlimited number of channels in your surround sound system.

This mode is similar to Dolby TrueHD and can be mainly found in Blu-rays as it is a larger file that cannot fit into DVDs.

If your receiver/pre/pro cannot process a DTS-HD Master Audio track, you will need a Blu-ray player or console player that can play and set it to LPCM for the processing to be done on the player and sent to the receiver via an HDMI connection.

4.      DTS-X

DTS-X is an object-based sound format and decoding mode and is a direct competitor to Dolby Atmos but is different in that it does not need height, up-firing, or even ceiling speakers to create an immersive experience.

With DTS-X, you can create a 3D surround sound effect with your 5.1 or 7.1 home theater speakers. But you will need a processor that can decode DTS-X and a DTS-X soundtrack or you could use your player to decode the soundtrack and send it to your receiver or preamp via HDMI.

DTS-X is more flexible and can work in a variety of home theater environments and speaker layouts and will even work with height speakers if they are available.

5.      DTS-X Pro

DTS-X Pro is a newer DTS decoding mode that is an enhanced version of DTS-X that can reach up to 30.2 channels, unlike DTS-X that can only reach up to 11.1 due to limitation in processing power and licensing hurdles.

You can use DTS-X Pro to decode a DTS-X soundtrack for an immersive object-based surround sound experience with more channels for more 3D precision.

6.      DTS Neural-X

DTS Neural-X is an alternative to Dolby surround that can be used to up-mix mono, stereo, or surround sound DTS soundtracks for an immersive surround sound experience depending on your home theater system and speaker layout.

However, you will need a receiver/pre/pro that has Neural-X decoding to create virtual channels for up to 11 channels.

7.      DTS Virtual:X

DTS Virtual:X is another 3D object-based processing mode that can work in any speaker layout even if you are using a soundbar for your entertainment needs.

This decoding mode will need a receiver/pre/pro or even soundbar that includes Virtual:X in its post-processing. You do not need height/ceiling/up-firing speakers or surround sound as you can create a virtual and simulated 3D effect even with a two-speaker system.

This is a great processing mode that can save you money and will not need a lot of space for a great movie-watching experience. It does this by tricking your ears into hearing things around you in a 3D space using spatial audio signal adjustments and delays.

If you are interested in this processing mode, you should ensure that it is listed on the sound processor you buy whether it is a sound or even a preamp.

Dolby Digital VS DTS: Surround sound comparison table

FeaturesDTSDolby Digital
Audio CompressionThe Compression in DTS is usually about 3 times less than Dolby Digital meaning that the file sizes and larger.Sound compression is 3 times more than DTS with the soundtracks needing less space meaning that it can be fitted into smaller storage such as DVDs.
Surround sound CodecsSurround sound codecs are available.Surround sound codecs are available.
Object-based surround soundHas codecs and processing modes that can create both a real and simulated 3D effect without needing height speakers.Can create both a real and virtual object-based effect but will usually need height speakers in most cases unless you are using Height virtualization.
Dynamic rangeCan create a more and better dynamic range depending on your surround sound system.Can create a more and better dynamic range depending on your surround sound system.
Speaker qualityDTS can work on both entry-level to high-end speakers with its advanced bass and equalization features.DD does not work always work well on entry-level speakers and will need a higher-quality system for you to feel the full immersive effect.
Audio outputAudio output and quality is the same as Dolby Digital.The audio output is the same as DTS. No significant difference in sound quality.
Data deletion capabilitiesCan delete corrupt and useless data.Can delete corrupt and useless data.
Additional featuresCan be burned into a CD or DVD and can be found in streaming services such as Netflix and Disney+.

 

Does not have a live feature as Dolby Digital does.

Also allows burning into CDs and DVD and can be found in online streaming platforms but is more readily available than DTS.

 

Has a live feature meaning that the technology can be used in live video and movie streams and other streaming events.

Alternatives to DTS and Dolby Technologies

Auro 3D

Auro 3D is an equivalent of Dolby Atmos and DTS-X for a 3D surround sound system. But unlike DTS-X, Aura 3D will need extra height, ceiling, or up-firing speakers to complete the setup.

This codec is mainly found in Blu-ray discs and as a processing mode in some receivers/pre/pros. However, Auro 3D is backward compatible meaning that you can have a full 5.1 or 7.1 surround sound in your home theater if your receiver is not Auro-3D enabled but when playing Auro-3D content.

But to enjoy the Aura 3D effect, you will need a minimum of 10 channels in your setup with 5 surround speakers, 4 height speakers, and at least one subwoofer. The available Auro 3D content is limited.

THX decoding modes

To use THX decoding modes, you will need a THX-certified processor. This can be used to process content that has been encoded by DTS and Dolby Digital using modes such as Cinema, Music, and Games that are equivalent to Pro Logic modes.

THX-certified receivers, preamps, or processors also come with an equalization software that can be used in THX audio processing without overriding the original soundtrack codecs.

You can also find THX-certified content that comes with an equalization soundtrack for better home theater calibration and improved sonic consistency.

IMAX Enhanced

IMAX enhanced is not much of a processing mode but a home theater content certification format aimed at providing the best audio and video quality possible for your movie watching needs.

You will often find TVs, Blu-ray discs, online movies, and even receivers with the Imax enhanced badge to show that the product is of a certain standard.

This worth mentioning since it can be confusing if you find an Imax enhanced logo next to a DTS or Dolby badge.

The final verdict on DTS vs Dolby Digital

Dolby Digital vs DTS is a topic that is highly debated with a divide on which technology is better and which one can provide higher audio quality.

Many, especially audio nuts will claim that DTS is better because of the higher encoding bit rate during compression while others, especially most average home theater users will find Dolby to be much better because of the superior audio processing for better dynamic range.

However, we cannot come to a conclusion on which one is better for you using the compression and processing numbers alone.

There are many things to consider when deciding between the two including what kind of speaker layout you have and personal preference because how we hear and perceive sound is very subjective.

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3 thoughts on “Dolby Digital vs DTS surround sound codecs and processing modes”

  1. DSU vs Neural:X for 2.0 content / 5.1 speaker layout

    I know this topic was discussed many times before all over the internet. however, rarely if at all I saw any reference on two uses cases that are in my interest. so i am hoping to get an answer here:

    Use case 1: Stereo 2.0 content with a 5.1/7.1 speakers layout
    Use case 2: rather to use an upmix on 5.1 content in a 5.1 speaker layout.

    1. what’s different about Dolby Surround and Neural:X on my specific use case? i.e. Which one works better with Stereo 2.0 content with a 5.1/7.1 speakers layout?

    2. if i have a 5.1 speaker layout, is there any added value using the Dolby Surround upmixer / DTS Neural:X upmixer for a 5.1 content (e.g. DD / DTS)?
    and if so , which one would most likely result best (5.1 content on 5.1 speaker layout with what upmix mode/technology)? would it enhance anything?

    Reply
  2. What I understand from your question is that you are wondering which processing mode would be great for your system. If that is the case, it will come down to your source material. Dolby Surround can only be used to upmix standard 5.1, or 7.1 files and add an extra height channel to emulate Dolby Atmos. But Neural-X can upmix a mono, stereo, and surround sound file and send a signal to your speakers for up to 11 channels.
    So, for a stereo file (2.0 channel), you would be better off using Neural-X since it is the one that can decode and upmix a 2.0 channel for your surround sound speakers, assuming that you are not using more than 11 speakers.
    To answer your second question, both Dolby True HD (for Dolby True HD content) and DTS-HD Master Audio (for DTS-HD content) can be used to play 5.1 files depending on how the soundtrack was encoded. If any of these codecs are used, your receiver/pre/pro should be able to detect them and switch to the respective mode should it happen to have both modes.
    When it comes to sound enhancement, none of these processing modes can add value to the already existing soundtrack but some details can be stripped away when using a lossy processing mode (hint: most of us can’t even pick up the differences). It will all come down to what sound best to you, if there are any differences at all to start with, when it comes to hi-res audio quality.
    I hope I have answered your question.

    Reply

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