If you have heard about Dolby Digital Plus and Dolby TrueHD, you may not truely understand the differences between them. While they look and operate similarly to the consumer, they are actually very different from one another. But how is that so?
Dolby Digital Plus provides a lossy or compressed audio signal while Dolby TrueHD provides a lossless or almost fully uncompressed audio signal. Both can include Dolby Atmos, but at different quality levels. Dolby Digital Plus doesn't provide as much detail in the audio as Dolby TrueHD.
As a result of using different compression formats, these technologies host a number of varying features too. Such as bandwidth requirements, size, and more. To completely understand how these sound formats differ, continue reading!
What is Dolby Digital Plus?
Dolby has come up with a ton of different audio codecs over the years. However, following the need to solve the problem of limited bandwidth with expanding surround sound technology, Dolby Digital Plus was born.
With HDMI along with other technologies catering to various resolutions, including 3D capabilities, networking support, and more, there was a scarcity of left bandwidth for supporting surround sound.
Needless to say, the growing trend of smart devices only fuelled the need for surround sound formats that were low-bandwidtch and efficient.
And, Dolby Digital Plus became the perfect solution. Mainly because of online streaming, the audio format grew in demand everywhere.
Using Dolby Digital Plus, users were able to enjoy amazing surround audio quality without depending on high bandwidths.
That said, this technology uses a lossy audio compression format. To be precise, the transmitted file losses some of the data when converted to digital sound.
This actually helps in reducing the bandwidth requirement. Plus, there isn’t a noticeable difference in the sound quality from the original file.
What is Dolby TrueHD?
Dolby TrueHD is another surround audio format popular in home theatre systems. Developed by Dolby, the codec support extends to Blu-ray Disc as well as HD-DVD programming content.
In contrast to Digital Plus, the Dolby TrueHD audio format makes use of lossless compression. Therefore, it provides audio effects almost exactly the way it was recorded. This is why, using the Dolby TrueHD audio codec, consumers can get an extremely high quality audio experience from their sound systems.
Not just that, the technology captures the various intensity of sound, mimicking the exact effect from the actual recording. To put it simply, the sound from the far places will feel faint. In contrast, the ones close will be more clear.
There is a very small amount of lost data from the original file. It's almost indistinguishable for most experts. The data size of Dolby TrueHD is larger, and it requires higher bandwidth for transmission.
Dolby Digital Plus vs Dolby TrueHD
As you may expect, the major difference between these two lies in terms of their audio compression. While Digital Plus happens to be a lossy compression, the latter utilizes lossless compression.
Therefore, while the Dolby Digital Plus sounds amazing, there is some loss in the data quality. On the brighter side, it occupies less space and seeks less bandwidth as compared to the Dolby TrueHD format. Thus, making it perfect for streaming platforms like Netflix, Disney+, and Amazon Prime Video to save money on data processing.
On the other hand, Dolby TrueHD bounces back in competition by offering an authentic audio experience. From the unnoticeable sound to intense audio, it captures everything.
Feature Comparison Table
To get a better look at the difference in features of these two, let’s check the comparison in detail:
| Features | Dolby Digital Plus | Dolby TrueHD |
|---|---|---|
| 2 Ch Stereo | Lossless | Lossless |
| 5.1 Ch | Lossy | Lossless |
| 7.1 Ch | Lossy Max channels supported. | Lossless |
| Dolby Atmos | Supported (Lossy) | Supported (Lossless) |
| HDMI ARC | Compatible | Non-compatible |
| HDMI eARC | Compatible | Compatible |
Now that you know the difference, it will be simpler to feel it too when playing your soundtracks on each of the formats.
However, if you are using a single speaker or the one with no support for the latest audio codecs, it will be very difficult to differentiate between the two.
To actually experience how TrueHD differs from Digital Plus, you'll need to use a surround sound system with many higher-quality speakers. Most people can tell the difference when using a higher-end Dolby Atmos soundbar system or on a traditional surround sound system.
When you can hear the quietest of audio, the difference between Dolby TrueHD and Dolby Digital Plus becomes more pronounced.
With TrueHD, the sound will be more detailed as well as the experience will seem more impressive compared to Digital Plus.
How Audio Compression Works
The concept of digital sound gave way to audio compression. Unlike natural audio, digital sound requires a bit of tinkering for transmission between different devices.
With no human brain within these devices to apprehend the language, we need technologies to sort those things out.
That is why audio compression is so imperative to understand. Basically, the process involves compressing digital audio into data files that are smaller and more compact.
Given the limited space in our devices, the compression process is what makes it easy to store and transfer content between devices.
Technically speaking, the Dolby TrueHD, as well as Dolby Digital Plus, are different types of compression formats. Hence, they utilize varying ways of storing sound in our devices. Depending on which compression type these formats use, the end file after decompression will have data loss, or it may not.
Lossy and Lossless Compression
Lossless compression, used by the Digital TrueHD, restores the data of the compressed file completely after decompression. Hence, there is no reduction in file size. Also coined as reversible compression, the technology does not involve any noticeable data loss at all.
The advantage of using lossless compression is one can retain the sound quality of the original file completely. However, this technique demands higher bandwidth and storage space in devices.
On the contrary, lossy compression fails to restore the decompressed file back to its original form because of data loss. Frankly speaking, the loss is permanent, hence also known as irreversible compression.
Usually, the data loss is far from being noticeable. But the process does affect the sound quality a little bit when compared to lossless compression. The same difference is visible between Dolby Digital Plus and Dolby TrueHD.
Conclusion – Is Dolby TrueHD Better Than Dolby Digital Plus?
While the two sound codecs are different, it may become difficult to decide which one is better between the Dolby TrueHD and Dolby Digital Plus.
Mostly because the two can only stand out from one another if you have a highly capable sound system.
Dolby TrueHD is definitely a better choice over Digital Plus in terms of sound quality. However, there is no point in discussing it if your device does not support these codecs.
Hence, for those not ready to compromise with the sound quality and own an advanced surround sound home theatre system, TrueHD will be the right choice.
On the other hand, if the system does not support TrueHD, or it is fine to ignore the little edge that TrueHD brings with itself, Digital Plus would do the trick as well.
After all, even being a lossy sound format, Dolby Digital Plus does pack impressive audio quality.
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