# On DVD's, what is 2.1 channel audio? **URL:** \ **Category:** Factual Questions\ **Created:** [October 13, 2006, 5:34am UTC](https://boards.straightdope.com/t/on-dvds-what-is-2-1-channel-audio/376277 "2006-10-13T05:34:22Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Surbey](https://avatars.discourse-cdn.com/v4/letter/s/4491bb/32.png) [@Surbey](https://boards.straightdope.com/u/Surbey)\ **Post date:** [October 13, 2006, 5:34am UTC](https://boards.straightdope.com/t/on-dvds-what-is-2-1-channel-audio/376277/1 "2006-10-13T05:34:22Z")
Is that directors commentary? I’m trying to save space on DVD’s and improve quality. Since the 2.1 channel audio usually takes up a fair share of space, I could get rid of it if it turns out to be dc. Any help? ---
**Author:** ![drillrod](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@drillrod](https://boards.straightdope.com/u/drillrod)\ **Post date:** [October 13, 2006, 6:15am UTC](https://boards.straightdope.com/t/on-dvds-what-is-2-1-channel-audio/376277/2 "2006-10-13T06:15:41Z")
It’s not the Commentary Track. It’s the audio track for a sound system set up in 2.1 mode, which if I remember right is basically stereo sound. Generally on DVDs this is opposed to Dolby Digital 5.1 meant to be heard on a surround-sound system with 4 side speakers, one central speaker and a subwoofer (5 speakers + 1 woofer = 5.1) If you’re trying to save DVD space, you could probably get rid of it, since I believe that the 5.1 audio track will still play ok on lesser systems. I can’t swear to that though. I’ll wait for a true audiophile to come along and correct me. ---
**Author:** ![bouv](https://avatars.discourse-cdn.com/v4/letter/b/bc8723/32.png) [@bouv](https://boards.straightdope.com/u/bouv)\ **Post date:** [October 13, 2006, 7:19am UTC](https://boards.straightdope.com/t/on-dvds-what-is-2-1-channel-audio/376277/3 "2006-10-13T07:19:35Z")
2.1 means stereo sound with a subwoofer (that’s the .1) The first number indicates the number of speakers, common ones are 2, 4, 5, and 6. Two is stereo, 4 is two front, two back, five is two front, two back, one center, and 6 is three front, three back (one left, one right, and one center.) And as said, most are .1, which is the addition of a subwoofer. But I could be wrong…but I don’t think I am. ---
**Author:** ![Wheeljack](https://avatars.discourse-cdn.com/v4/letter/w/838e76/32.png) [@Wheeljack](https://boards.straightdope.com/u/Wheeljack)\ **Post date:** [October 13, 2006, 7:42am UTC](https://boards.straightdope.com/t/on-dvds-what-is-2-1-channel-audio/376277/4 "2006-10-13T07:42:51Z")
That’s weird. Where would you find a system capable of playing more than two channels outside of a 5.1 setup? Is this something that’s currently available retail? And if so, what is the point? I’m assuming this is wrapped up in a digital out from the DVD player, since it’s more than two channels. Couldn’t your speaker hardware just pull the sub sounds out of a pair of analog signals and send them to the subwoofer, like a car stereo? Soooo confused… I guess my question is why someone would bother with all this digital hardware for left, right, and sub, with no surround and no center channel. Please to be explaining! ---
**Author:** ![slortar](https://avatars.discourse-cdn.com/v4/letter/s/6bbea6/32.png) [@slortar](https://boards.straightdope.com/u/slortar)\ **Post date:** [October 13, 2006, 1:18pm UTC](https://boards.straightdope.com/t/on-dvds-what-is-2-1-channel-audio/376277/5 "2006-10-13T13:18:05Z")
[QUOTE=Wheeljack] That’s weird. Where would you find a system capable of playing more than two channels outside of a 5.1 setup? [/QUOTE] Oh, there’s about a cubic million older audio formats. I’ve also seen dolby 3.0 (left/right/center) and 4.1 before. I assume 4.1 was left/center/right/rear surround + sub. The Zardoz dvd had 3.0 and an import of Hellraiser was in 4.1. 2.1 is sort of an inaccurate way to describe it because the sub’s not really a discrete separate channel. Basically, you can always “break off” part of a standard stereo signal and send it to a subwoofer for added punch. You might as well start calling dolby mono “dolby 1.1”. 😃 ---
**Author:** ![asterion](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@asterion](https://boards.straightdope.com/u/asterion)\ **Post date:** [October 13, 2006, 1:43pm UTC](https://boards.straightdope.com/t/on-dvds-what-is-2-1-channel-audio/376277/6 "2006-10-13T13:43:19Z")
My computer has 4.1. If you position the left and right speakers properly, you don’t really need the center channel. ---
**Author:** ![Wheeljack](https://avatars.discourse-cdn.com/v4/letter/w/838e76/32.png) [@Wheeljack](https://boards.straightdope.com/u/Wheeljack)\ **Post date:** [October 13, 2006, 3:04pm UTC](https://boards.straightdope.com/t/on-dvds-what-is-2-1-channel-audio/376277/7 "2006-10-13T15:04:59Z")
Well, you learn something new every day. Now that I think about it, I bought some speakers that supported 4.1 for my computer, but my soundcard didn’t, and I never saw any games that claimed to support it either. I figured it was something the speaker manufacturer made up to sound cool. 🙂