Dolby Digital vs. Dolby Digital Plus: What’s The Difference?

The term “Dolby Digital” is one that we are all familiar with because we notice it so frequently, but many of us don’t know the first thing about it. 

We often see this phrase and the logo on a computer’s spec sheet, at the beginning of movies, or on those DVD cases back in the day.

Dolby Digital is one of the most extensively used surround sound formats on the market. This technology is used to record and playback audio soundtracks for various media, including TV shows, movies, video games, and DVDs. 

The Dolby Digital format has been around since 1992, but it has recently been replaced by a newer version, the Dolby Digital Plus. 

This article seeks to clarify the differences between the two and remove any ambiguity.

Dolby Digital

Dolby Laboratories created the audio compression format known as Dolby Digital. Initially, it was created to be the primary audio format for cinemas, but later on, it was used in compact discs (CDs) and digital versatile discs (DVDs). 

Today, it is also utilized for satellite-delivered TV and radio, digital video streaming, Blu-ray discs, and gaming consoles. 

It can get confusing because this format has had several names over the years, including DD 5.1, AC-3 (Audio Codec- 3), ATSC A/52, Dolby Surround AC-3, and  Dolby Stereo Digital. 

You will often encounter the term 5.1 when talking about Dolby Digital. 

The name comes from the fact that there are five channels of audio — left front (L), right front (R), center (C), left surround, and right surround — plus one channel for low-frequency effects (LFE), which is necessary for particular sounds and action sequences in movies. 

The “5” part refers to the number of channels in total, while “1” refers to the subwoofer channel. 

This is a significant improvement to Dolby’s previous technologies, like Dolby Stereo in 1975, which took the conventional stereo sound and created a 4-channel surround experience in the theater, the Dolby Surround. It first introduced the mono-surround channel to the usual front, left, and right.

Dolby Digital Plus

The Dolby Digital technology, which has become the industry standard, is succeeded by Dolby Digital Plus. Dolby Digital Plus offers more channels, less compression, and more excellent data rates than standard-definition DVDs. It offers a warmer, richer, and more compelling audio experience.

Dolby Digital Plus was created to elevate the high-definition video experience. It is a more advanced surround sound codec, which is why it’s commonly used by streaming services like Netflix and Amazon Prime Video.

Like its predecessor, Dolby Digital also has a handful of nicknames, including DD+, Enhanced AC-3, and simply E-AC-3. 

Dolby Digital Plus can handle up to 7.1 discrete channels when used with Blu-ray Disc material. However, this technology is built to be scalable and can eventually handle up to 15.1 discrete channels while still working with all Dolby Digital Plus decoders.

Breaking Down the Differences

For many years, Dolby Digital has been the standard for delivering surround sound to movie theaters and homes. 

It’s also the most common format for DVD and Blu-ray discs. But with so many different types of media coming out these days, a new format called Dolby Digital Plus has emerged as an alternative. 

So how do these two formats differ from each other? Let’s find out.

1. Sound Channels

One of the main differences between these two types of audio is that Dolby Digital supports up to 5.1 channels of sound while Dolby Digital Plus supports up to 7.1 channels.

This means the latter can produce sound from more directions, translating to more immersion when watching movies.

2. Sound Quality

Dolby claims that Dolby Digital Plus can deliver up to five times the audio quality of standard Dolby Digital when used on high-resolution digital TVs or Blu-ray players capable of playing back 24-bit/192kHz audio files. 

The increased fidelity would allow you to hear more detail in music, dialogue, and sound effects than with standard Dolby Digital encoding.

However, this may not be noticeable unless you have a very expensive home theater system with top-notch speakers and amplifiers.

3. Support

Both Dolby Digital and Digital Plus support stereo audio, HDMI, and S/PDIF ports. 

However, Dolby Digital Plus has the advantage of being able to support the revolutionary spatial audio technology Dolby Atmos.

4. Data Rate

Dolby Digital offers high-quality content in larger file sizes. On the other hand, Dolby Digital Plus delivers high-quality information in smaller file sizes.

This is why the Plus version is widely used by streaming and broadcasting services.

Here’s a comparison table to differentiate the two at a glance:

How Can I Use Dolby Digital Plus?

To experience Dolby Digital Plus, you can invest in home entertainment equipment that features the said technology, including A/V receivers, Blu-ray players, or Smart TVs. 

Access to this technology is also available through PCs, tablets, and mobile devices. Dolby Digital Plus is also a fundamental format for Windows 10 and the new and improved Microsoft Edge browser. 

Similar to Blu-ray Disc, Dolby Digital Plus-encoded media can be found on streaming services like Netflix, Vudu, and Amazon Fire TV.

Conclusion

For the average consumer, Dolby Digital and Dolby Digital Plus are practically identical. 

Both are great technologies designed to enhance your home theater experience. It should come as no surprise that Dolby Digital Plus is the more advanced of the two since it is built upon the other. 

We hope that this article has given you a better understanding of the differences between Dolby Digital and Dolby Digital Plus. 

In the end, this is an ever-changing technology and might evolve much more in the future.