Any reason to use DD5.1 Audio instead of DD2.0 when encoding to 2ch MP3 audio?

[TrueDis]

I'm just wondering if there's a reason to pick the DD5.1 track on most DVDs instead of the DD2.0 track (which is already stereo, so it needs no downmixing) when encoding to an MP3 audio track. Thanks.

[tangent]

Pros for DD5.1
- If you want just L and R channels without Dolby Surround (with SL mixed into L and SR mixed into R instead of both being mixed into both L and R), then you need to use the DD5.1 to do this. Maybe better encoding quality because less entropy in channels.

Pros for DD2.0
- Downmix done by pros
- Faster transcoding
- Maybe better quality because less audio processing before encoding

[TrueDis]

What would the Azid options be for using a DD2.0 input file? Do i have to fool with the --stereo=stereo option or anything like that?

[LigH]

Because DD 2.0 does not contain back channels which Azid could mix into the front channels, the stereo mode in unimportant, you better disable the explicit use of this option (allow Azid to use its default setup).

[rmatei]

In my opinion, and that's just my humble non-audiophile opinion, downmixing the 5.1 sounds better. Well, they both sound good, but maybe the 2.0 track is designed with low quality speakers in mind (like TV's internal speakers). If you have speakers that handle a bit of bass and dynamic range, I think 5.1 through azid sounds better, because it seems to have more of just that: bass and dynamic range.

Now I pass my audio to a receiver and a 5.1 system, so I choose the 5.1 downmix because I can reconstruct the surround sound to some degree with Dolby Prologic.

[Slogra]

DVD players can't downmix DD 5.1 to Dolby Surround very well, so an extra DD 2.0 track is added to the dvd especially for people with a Dolby Surround System. So use this DD 2.0 track.