Just like music, surround-sound formats come in many standards. The two most popular ones supported by a broad range of high-end audio systems are DTS and Dolby Digital. The battle of DTS vs. Dolby sound is a hotly debated issue. Some audiophiles argue that DTS is capable of delivering better sound quality than its counterpart, Dolby Digital.
This reasoning arises probably because DTS surround sound is usually encoded at a higher data rate than the corresponding Dolby formats. Others argue that Dolby Digital is far more advanced and so is its sound quality. In its defense, Dolby maintains that their codec is more efficient and thus can operate at a lower bit rate. So which one of these two multi-channel sound formats is more superior? Read on to find out.
What Are DTS and Dolby Digital?
Dolby Digital is the name for audio compression technology developed by the Dolby Labs. DTS stands for Digital Theater Systems, a popular home theater audio format that was developed in 1993 as a competitor to Dolby Labs in the development of surround sound audio technology for movie production. Both DTS and Dolby Digital provide surround sound codecs for 5.1, 6.1 (rare) and 7.1 setups where the first number represents the number of small surround speakers, and the “1” is a separate channel for a subwoofer.
Both formats utilize “perceptual” data reduction techniques to remove useless data in PCM signal output, thereby preserving high fidelity sound. In addition to the 5.1 to 7.1 speaker playback, different formats offer cutting edge audio technology geared toward enhancing the sound quality. For instance, DTS and Dolby Digital use compression to save space either on the disc, as is the case with Blu-Ray and DVDs or on streaming bandwidth for services like Netflix.
Some versions of Dolby Digital and DTS are “lossy” which means they have a degree of audio degradation from the original source while others are lossless. Dolby, for example, has a lossless version, Dolby TrueHD, and a lossy version, Dolby Digital Plus. The lossy version takes up very little space on Blu-Ray discs. DTS also has a lossless version, DTS-HD Master Audio, that supports 7.1 channels speaker setup.
Differences Between DTS and Dolby Digital
The main difference between DTS and Dolby Digital is seen in the bit rates and compression levels. Dolby digital compresses 5.1ch digital audio data down to a raw bit rate of 640 kilobits per second (kbps). However, the 640kbits/s is only applicable to Blu-Ray discs. The maximum bit rates that Dolby Digital can support for DVD Video and DVD audio is up to 448kbits/s.
To squeeze in all the relevant data, Dolby Digital employs a variable compression of around 10 to 12:1. DTS surround sound, on the other hand, applies a maximum raw bit rate of up to 1.5 megabits per second. However, that bit rate is limited to approximately 768 kilobits per second on DVD video. Due to the higher bit rate supported by this format, DTS requires significantly low compression of about 4:1.
In theory, the lesser the compression used in the encoding, the more realistic the sound becomes as it better represents the original source. What this means is that DTS has the potential to produce better sound quality than Dolby Digital. Here’s a breakdown of the various versions you’ll find in each standard and their bit rates.
- DTS Digital Surround – 5.1 maximum channel sound at 1.5 Mbps
- DTS HD Master Audio – 7.1ch maximum sound at 24.5 Mbps (lossless quality)
- DTS HD High-resolution – 7.1ch maximum sound at 6 Mbps
- Dolby Digital – 5.1ch maximum sound at 640 Kbps (common in DVDs)
- Dolby Digital Plus – 7.1ch maximum sound at 1.7 Mbps (supported by streaming services like Netflix)
- Dolby TrueHD – 7.1ch maximum sound at 18 Mbps (lossless quality available on Blu-Ray discs)
Which One Is More Superior?
Comparing DTS and Dolby Digital in consumer applications reveals that both standards are closer in terms of audio performance. By looking at the specs above, DTS seems to have an edge against Dolby due to the higher bitrate in all of its three versions. However, higher bitrates don’t always mean higher quality. There are other factors such as signal to noise ratio and dynamic range that some audiophiles might consider better in Dolby rather than DTS.
Most modern receivers come with support for both DTS Master Audio and Dolby TrueHD, so you may not even have to choose between the two. But if you are an audio enthusiast and want something extremely gorgeous, you might want to look into technologies such as DTS:X or Dolby Atmos as well as receivers and home theaters that support them. However, in the rare occasion that you have to choose between DTS and Dolby Surround, go with DTS due to the higher bitrate.
Determining which format has superior sound quality is a very ambiguous matter, as there are many factors to consider besides bit rates and compression levels. So where does this DTS vs. Dolby debate lead? Both audio formats are capable of achieving nearly similar results delivering surround sounds.
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