One of the main components of a home theater setup is the sound system. Generally to qualify as home theater, a system needs to have some form of surround sound.

The only problem? There are so many different formats and setups for home theater sound. It’s enough to make your head spin!

That’s why we’re starting a new series on the Home Theater Installation of Orange County blog today: Understanding Home Theater Sound Types. We’ll start today with one of the earliest formats that’s still in wide use: Dolby Digital.

Prologue: Defining Terms

Before we dive into Dolby Digital, we need to define some terms. In the world of home theater speaker setups, you’ll often see numbers, like 5.1 or 7.1, in addition to branded names, like Dolby Digital or Atmos. Both of these are important. We’ll cover the branded names later on, but first let’s look at the numbers.

If you see a number like 5.1 or 7.1, you’re seeing a shorthand description of the number of speakers. A 5.1 system has five distinct speakers, plus a subwoofer (that’s the .1).

Whatever numbers are associated with your speaker system, you’ll also need a receiver that can handle that many channels of audio. So a 5.1 system needs a five-channel receiver, and a 7.1 system needs a seven-channel receiver.

Dolby Digital: The OG Surround Format

Dolby Digital is the original surround sound format. It was the first to provide clear, realistic multichannel audio in a 5.1 channel configuration (Front left/center/right and rear left/right). When used on discs (such as DVDs), audio must be compressed. The receiver then decompresses and plays the audio.

This compression isn’t particularly desirable among enthusiasts, but everyday folks probably won’t hear a difference—especially on non-premium speakers.

Bonus Format: DTS

DTS is a less common format in the same family as Dolby Digital. It improves on Dolby Digital by lowering compression levels. The difference is slight, however.

Interested to learn more? Stay tuned! We’ll cover many other formats in the weeks to come.