Dolby Digital Vs. Dolby Digital Plus: what’s the difference?

There’s a lot of noise around the audio formats you choose, whether it’s listening to music or surround audio from your favorite movies and shows. But there are plenty of options, even if you’re considering a proprietary format like Dolby Digital. From Dolby Technologies only, we have Dolby Digital, Dolby Atmos and Dolby Digital Plus. If you’re wondering what the big difference is, you’re not alone.

Dolby Digital, in general, is an audio compression technology used for multi-channel immersive and surround audio. In order to efficiently fit digital audio data onto physical media such as disks or to make it available for delivery over wireless and over-the-air channels, the data is compressed. It is scaled down or scaled down to provide faster transmission, hopefully better performance, and ensure that the whole process requires fewer resources, making it more efficient. True lossless compression aims to reduce file size and handles eventual reconstruction without sacrificing any of the original data or its quality. Lossy, which is what Dolby Digital audio is, tries to get as close to it as possible.

Dolby Digital is a format that supports 5.1 channel audio. Dolby Digital Plus, the latest and upgraded version, is a format that supports 7.1 channel audio and above. While not necessarily relevant here, Dolby Atmos is similar, but designed to be an object-based format that adds height audio channels to create more of a 3D sound. It generates an audio bubble that makes it seem like sounds are coming from all around you, like in traditional surround, left and right, but also from above or below. All in all, that’s the difference between the three, but what does it actually mean?

To make things a little easier to understand, let’s compress the terms right away, just like our audio streams. Beyond the Dolby Audio versus Dolby Atmos arguments discussed in the introduction, we can establish that Dolby Digital and Dolby Digital Plus are the company’s primary audio formats. Dolby Technologies actually offers more, including Dolby TrueHD, Dolby Volume, Dolby Pro Logic llz, and Dolby AC-4. They are all designed for specific uses.

Dolby Digital, the original, was intended for home theater stereo surround, with until six channels of amplification on five speakers and a subwoofer: front or center, left surround, right surround, left channel and right channel. The “up to” is important because you can also have less, including mono, 2 channel and 4 channel configurations. Dolby Digital Plus is an enhanced format, offering better data bandwidth and improved sound, as it offers higher bitrates than the original. It also supports more amplifier channels, starting at 7.1 channels, which adds two additional speaker options via left and right surround back. It is backwards compatible, if you are watching media that only supports the old format, but with upgraded content you will be able to experience the new improved compression and added channels.

For the layman, Dolby Digital Plus means that home theater solutions will perform much better, surpassing the quality of previous systems and technologies to give you a truly immersive and cinematic setup. Some of the best ways to test your surround sound, an established or new setup, involve playing Dolby Audio compatible songs, recordings of live concerts, playing games, and playing well-known audio scenes from blockbuster movies. “Master and Commander: The Far Side of the World” has an incredible audio track.

Technically, yes, to fully experience the new uncompressed and enhanced Dolby Digital Plus audio, with Dolby Atmos, you need hardware that supports the technology. This includes your TV, media player, and surround sound equipment, depending on what you have installed in your home. However, the real answer is a little more nuanced. Since the technology is backwards compatible, if you watch media supported by Digital Plus, you can still enjoy it in 5.1 channel audio, provided your equipment supports it.

Any Digital Plus stream will be converted to a standard Digital 5.1 bitstream, with the two additional channels integrated into the current configuration. So what would normally go to the surround back speakers is output to the left and right surround channels. You shouldn’t lose any sound, it will just sound a little different with an older format system.

To bring things home, this means that if you are happy or satisfied with your current surround and home audio setup, you don’t necessarily need to upgrade, especially if it works fine as is. But if you want to enjoy more modern, enhanced, and immersive audio, the promotion might be worth it. If you have an aging system, there are many exciting new technologies that can improve your home theater that are worth considering. Please note that some of these descriptions are extremely simplified to make the information easier to digest.