BeSweet: stereo, surround or surround2 ?

[palesi]

I'd appreciate some advice from you audio quality purists :)

First situation: I am converting a 5.1 AC3 file to OGG format with BeSweet. Regarding "Channels Mode", is there any quality loss if I select "surround" or "surround2" instead of "stereo", when playing on a normal set of 2-channel stereo speakers? Since i don't have Dolby Surround or Pro Logic equipment right now, but may get some in the future.

Second situation: same as above, but this time I am converting a 2 channel AC3 file.

Also, does low OGG quality affect surround presence in any way?

[empty]

quality loss if I select "surround" or "surround2" instead of "stereo", Yes, because of the surround information in your audio , you have less bitrate for the pure stereosignal.
I am converting a 2 channel AC3 file. Huh, it's an authoring issue. You can't help it, if the 2-channel-AC3 is pure stereo, DPL or DPLII.;)
does low OGG quality affect surround presence in any way? Yes, because the low bitrate affects the overall signal.
bb empty

[palesi]

Yes, because of the surround information in your audio , you have less bitrate for the pure stereosignal.

Is it a noticeable quality loss?

I ask that because I've seen that The OggMachine sets "surround2" Channels Mode by default. Now, I trust DSPguru thoroughly, but since most computer speakers aren't Dolby Pro Logic II optimized, and few people can afford to hook up the soundcard's audio out with the DPLII capable home stereo, this choice would seem a bit out of place, correct me if I'm wrong.

Also, surround mode is suggested in most of the guides.

[palesi]

I've just found this thread:

http://forum.doom9.org/showthread.php?s=&threadid=36464

Sorry, didn't find it before.

So, i guess my choice will be plain "stereo".

[nuked]

yes stereo is better. Bit rate isn't the whole issue. There's still info mixed in from the back speakers either way that must be compressed either way and it's still audible either way and SUPOSEDLY "stereo compatible" either way. It may waste a FEW less bits in stereo mode because more stuff is in phase although with movies where there's not that much channel correlation I don't think it will save so many bits, but mostly, even if compressed in quality mode(constant quality regardless of file size).. it will just sound a little better in stereo IMHO, becuase "compatibility" is NOT exact. Have you ever plugged in one of your 2 speakers backwards? Sounds kinda strange right like the sound is pulling on your ears almost or something. That's exactly what happens to the surround signal encoded in stereo. A little of that is natural and adds add a bit of ambiance to the sound even possibly a virtual surround effect.. but too much of it artificially added also loses focus and sharpness in my opinion. as you say, use stereo, but compare for yourself. This is the whole reason for my very long boring thread on digital formats. I'd like to store some limited surround info without screwing up my stereo playback quality.