Encoding AC3 to mp3 - what is best method?

[mironto]

I want to encode AC3 to mp3 2 channels through graphedit and want to know which setting to use for InterVideo - Stereo or Dolby Surround (I have SB Live with 4 speakers)? What's the difference? May I encode the dolby wav with Lame?

...um, that's it for now...

[Enchanter]

That depends on which you prefer. Most of my sources have always been 2.0 and converting to Dolby Surround always ruins the audio experience. Hence, I've always sticked to simple Stereo. It is not necessarily the same with 5.1 sources though.

By the way, either Stereo or Dolby Surround will give you only 2 channel output, NOT 4 channel.

[mironto]

I have AC3 5.1 source and I know that I'll get only 2 channel (want to go for 1CD) from both Stereo and Dolby, but want to know which one will sound better on 4 speakers (or this way - is dolby adding some more information when decoding on card like SB Live to create quasi surround effect? I've notticed this on some movies that the sound really came from rear speakers and source was only 2 channels).

[Enchanter]

Originally posted by mironto
I have AC3 5.1 source and I know that I'll get only 2 channel (want to go for 1CD) from both Stereo and Dolby, but want to know which one will sound better on 4 speakers (or this way - is dolby adding some more information when decoding on card like SB Live to create quasi surround effect? I've notticed this on some movies that the sound really came from rear speakers and source was only 2 channels).

The resulting audio WILL still be 2 channel. It is the soundcard that is recreating the rear channel audio using either 2X Stereo OR separating what it perceives to be background sound to the rear channel and playing the rest through the front channel. Dolby or whatsoever has nothing to do with it.

It is kind of hard to recommend exactly which mode to use, since some will like the STEREO Dolby Surround effect, while the rest prefer simple stereo. The only way to find out which you should go for is to do test files with both modes and listen to them. You can then decide which one is better.

[mironto]

Originally posted by Enchanter
It is the soundcard that is recreating the rear channel audio using either 2X Stereo OR separating what it perceives to be background sound to the rear channel and playing the rest through the front channel.

So in that separating process does it matter, if the stereo source is just stereo or Dolby Surround?

[Enchanter]

I'm not too sure about that since I'm not a big fan of Dolby surround, nor have I run any listening test on this. As I previously suggested, you might want to do some listening tests with both modes and decide which sounds better to your ears.

However, having owned a SB Live! and used their official driver (you are using the official driver, aren't you?), I can tell you that the card will treat a stereo source in the latter manner (non- 2X-Stereo). This may probably cause some 'funny' sound when coupled with a Dolby Surround effect. Do the test and find out for yourself.