The "point 1" (.1) channel of a surround system is one of the most confusing terms for consumers. Point 1 refers to the LFE or subwoofer in a surround system. The LFE, or point 1, only plays low-frequency audio material, yet receives its own discrete signal, so that mixing engineers can specifically send the deep bass to the subwoofer where it can best be reproduced in a home theater system.

Most commonly the .1 channel is an active subwoofer, though in some custom installations a passive, in-wall subwoofer is used.

You can find the .1 in such surround formats as 5.1, 6.1, and 7.1. These found on DVD, HDTV broadcasts, as well as Blu-ray.

In a 10.2 system, two LFE channels are used.

To decode a .1 signal you'll need a decoder, most often found in AV receivers and preamps.

For more information, visit our Subwoofer Review section.