# Dolby 5.1 = 5.1 channels of sound... ??? .1 ???

**URL:** <https://boards.straightdope.com/t/dolby-5-1-5-1-channels-of-sound-1/115350>\
**Category:** Miscellaneous and Personal Stuff I Must Share\
**Created:** [June 21, 2002, 11:06pm UTC](https://boards.straightdope.com/t/dolby-5-1-5-1-channels-of-sound-1/115350 "2002-06-21T23:06:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![flapcats](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@flapcats](https://boards.straightdope.com/u/flapcats)\
**Post date:** [June 21, 2002, 11:06pm UTC](https://boards.straightdope.com/t/dolby-5-1-5-1-channels-of-sound-1/115350/1 "2002-06-21T23:06:07Z")

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Someone - answer please, 0.1 channels of sound - I’m miffed.

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**Author:** ![The\_Tof](https://avatars.discourse-cdn.com/v4/letter/t/cdc98d/32.png) [@The\_Tof](https://boards.straightdope.com/u/The_Tof)\
**Post date:** [June 21, 2002, 11:24pm UTC](https://boards.straightdope.com/t/dolby-5-1-5-1-channels-of-sound-1/115350/2 "2002-06-21T23:24:31Z")

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I believe .1 refers to the subwoofer. (Since it’s the only channel that’s not completely required in the system-- or at least, is meant to augment the other 5 and not be a completely seperate speaker/sound in and of itself.)

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**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\
**Post date:** [June 21, 2002, 11:50pm UTC](https://boards.straightdope.com/t/dolby-5-1-5-1-channels-of-sound-1/115350/3 "2002-06-21T23:50:12Z")

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I think it’s more because the bass channel is non-directional because of the long wavelengths of the low frequencies. My theater system has five small satellites and it’s easy to localize each speaker’s location when doing setup. Your earbones do this by detecting the phase difference between the sound reaching each side of your head. That trick doesn’t work with low frequencies because the phase difference between each ear is undetectably small.