Home theater sound basics explained

Home theater surround system lingo can get confusing at times. Never fear, we’re here to help!

A typical home theater system is comprised of four main parts: the receiver, the speakers, the TV or projector, and the sources. The sources are whatever you happen to be watching or listening to (ex. Cable boxes, disk players, gaming systems, phonographs, streaming systems, etc). These sources are connected to the receiver. The receiver is the head unit that powers the speakers, sends video signal out to the TV or projector, and functions as the switchboard for all your sources. Modern receivers can also receive audio information from the TV and send it out to the speakers if, for example, if you’re watching Netflix on your Smart TV. Finally, the speakers are what produce the sound. These are typically passive; that is to say, they’re powered by your receiver.

A basic two-channel system would be composed of a receiver and a pair of speakers up front (called Front Left and Front Right). This is expressed like this: “2.0,” for two speakers and no subwoofer. If we add a subwoofer for additional bass, it turns into 2.1. Adding a center channel for dialogue clarity would change it to 3.1.

True surround sound begins at 5.1, composed of a Front Left, Front Right, Front Center, Surround Right, Surround Left, and a subwoofer. The next step up would 7.1 (the same as above but with two additional surround sound channels for a total of four, plus the three in front and a subwoofer). There are also 5.2 or 7.2 systems, adding an additional subwoofer.

Once we get to at least seven speakers, we also have the option of doing an Atmos setup. In traditional surround sound, an engineer goes through every frame of the movie and literally assigns that sound to the specific speakers to create surround effects. In an Atmos setup, the objects in the movie are instead assigned a “space” anywhere in the room and the receiver uses whatever speakers it needs to create the proper effect. This makes for a much more immersive, 3D experience. However, Atmos does require more speakers as well as dedicated height channels. Height channels are speakers designed to be mounted up high or to bounce off the ceiling to create that 3D audio effect of objects passing overhead.

Atmos setups add an extra digit to express the height channel. Traditional seven channel surround sound is expressed as 7.1. An Atmos setup would instead be 5.1.2 (five main speakers, one subwoofer, and two height channels). This can go all the way up to eleven and even thirteen total speakers and theoretically, dozens.

If you have any other questions or clarifications, come in or call to talk to our expert sales staff!