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?
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.
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.
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!
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”. 
My computer has 4.1. If you position the left and right speakers properly, you don’t really need the center channel.
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. 