Editing Low-frequency effects (section)

== Home theater systems ==

In the 1990s [[surround sound]] [[home theater system]]s became available to enhance the experience of viewing DVD and Blu-ray films. Prior to the advent of home theater systems, when VCRs were used, the enhanced sound option was stereo high-fidelity sound or [[Dolby Pro Logic]] for [[Dolby Surround]]-encoded tapes. With home theater systems, a multichannel audio system was used to deliver different sounds to six or more different speakers. The widely used 5.1-channel audio system consists of five full-range main (Left, Center, Right, Left rear Surround, and Right rear Surround) plus a Low-Frequency Effects (LFE) channel. Many typical home theater systems, especially [[home theater in a box]] systems, are incapable of accurately reproducing LFE in the 20 Hz range.

The LFE channel delivers bass-only information to supplement the overall bass content. The LFE channel content is not the same as the content of a subwoofer-out jack. The LFE channel is used to carry additional bass information in the surround sound programming, while the subwoofer output is bass information from up to all six channels that has been selected to be reproduced by the subwoofer via a [[bass management]] system.

The bass management in surround sound replay systems is that bass content in the incoming signal, irrespective of channel, should be directed only to loudspeakers capable of handling it. The bass management system may direct bass to one or more subwoofers (if present) from any channel, not simply the content of the LFE channel.