A channel is one independent stream of audio samples meant for one speaker position. Mono is a single channel, stereo is two (left and right), 5.1 has six, and an immersive 7.1.4 layout has twelve. Each channel is full-bandwidth except the LFE (.1), which is band-limited for the subwoofer. Channels are the traditional, speaker-bound way to carry surround: the mix is baked for a specific layout, and players downmix when the playback system has fewer speakers. Object-based formats like Dolby Atmos break this model by storing sounds with positional metadata instead, but channels remain the backbone of nearly all delivery today.
The book · Volume 4 of 7
Audio for Video: A Complete Guide to Sound in Video Products: From PCM and Codecs to Loudness, Accessibility, and Real-Time Voice Processing
A channel is the basic unit of every audio layout, and mismatched channel order is a classic cause of dialogue coming out of the wrong speaker. Volume 4 covers the channel in detail: mono, stereo, 5.1, 7.1 and 7.1.4 layouts, channel order, downmixing and how codecs carry multichannel audio. Written by Nikolay Sapunov, CEO at Fora Soft.
Dialogue coming from the wrong channel after transcoding?
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