[xcalibur]

I read an article on the rmix site saying that joint stereo produces better sound quality than stereo? is this true? why is that?

 

[john_jcb]

Based on my understanding of the process I would think the opposite would be true. Joint stereo is a technique where the data is compressed to save bandwidth. I am not sure how this could ever sound better than the unadulterated music.

 

[lextek]

I myself like the stereo. Joint I believe omits or combines information that is common to both channels, or something along those lines.

 

[PodMan]

For LAME, the developers themselves state joint stereo is the only way to get maximum quality. Even their insane setting uses joint stereo. A 320kbps joint stereo will sound better than a 320kbps normal stereo.

First, space and bandwidth is very limited when you are dealing with audio compression. A good Joint stereo implementation combines identical data from both channels, resulting in more bandwidth available to encode the rest of the data stream, resulting in higher overall quality.

it really depends on the encoder. Sony's LP4 compression scheme, for example, absolutely destroys stereo separation. Though I suspect it might have something to do with sacrificing stereo separation to gain higher overall fidelity at such low bitrates.

Refer to this thread for more information:

http://www.hydrogenaudio.org/index.p...=ST&f=15&t=995

 

[xcalibur]

thanks for the quick reply guys...so, say if i had the space to spare and i wanted highest mp3 quality i should use 320 CBR joint stereo? are you sure 'insane' is only for joint stereo? i tried putting the -m s behind the --alt insane tag and the command line said that i was encoding using 320 CBR with stereo mode...

 

[PodMan]

usually, I wouldn't add anything extra to the presets as they are internally tuned already. Doesn't -m s force stereo though? So maybe that's why it is encoding in stereo.

I am pretty sure if you just use alt preset insane it will end up with a joint stereo file like the rest of the presets.


This is from the first post of that thread, by the guy who developed the presets:

"5. Joint stereo is needed even at bitrates of 320kbps to achieve the best sound quality in some critical cases. Forcing stereo on everything up to 320kbps and then forcing joint stereo does not fix the problem (as user implies in one of those threads). I've tried this before. "

 

[xcalibur]

oh i see...thanks a lot for explaining it...i was wondering why i had to force stereo with insane..so looks like it wasn't something wrong with my Lame encoder...

 

[blessingx]

Joint stereo was frowned on for awhile because of bad implimentation. Now (as PodMan said), it should be used to free as much space as possible for everything else. Kinda like VBR at the lower settings.

Check the Transparency Poll for what people are currently using to approach CD quality. Also Hydrogen Audio for more info.

Plus there are many other formats including mpc and aac.

 

[xcalibur]

are there any decent pc aac encoders out yet (for use with latest ipod)?

 

[blessingx]

Quote:

Originally posted by xcalibur are there any decent pc aac encoders out yet (for use with latest ipod)?

Yes, better encoders than on the Mac at this moment. Read through info here. Trick is getting the tracks on the new iPods.

 

[xcalibur]

ahh..alright..thanks..but does the highest bitrate for AAC sound better than LAME insane quality?

 

[blessingx]

That's the big question.

I would guess. 320 aac should be better than 320 mp3, and it's reported 320 vbr aac can go higher if needed (not capped at 320 like mp3). I think there needs to be more testing, though. And this assumes all encoders are equal. Is for example Apples mp4(acc) encoder better at 320 than lames mp3 at 320? Not sure. Unfortunately (for my ears, not for my wallet) my setup hits transparency before either (around --ape), so I can't test. I will say the few 128 mp4's I bought off of Apples store sounded better than the 160 mp3s I have around here. Probably closer to 192, but I don't think quite reaching it. Have to do more testing.

 

[MacDEF]

Quote:

Originally posted by PodMan For LAME, the developers themselves state joint stereo is the only way to get maximum quality. Even their insane setting uses joint stereo. A 320kbps joint stereo will sound better than a 320kbps normal stereo.

This is a bit misleading. The fact of the matter is that if you take a joint stereo track and a stereo track that are otherwise identically encoded, the stereo track will sound significantly better -- but the stereo file will also be bigger.

However, where joint stereo helps is that by using joint stereo (which encodes one bit of data when the left and right channels are identical, instead of one bit of data for each channel, thus saving space), you free up space to better encode the rest of the audio signal. So when comparing two files of the same size (which two songs at the same bitrate should be), the joint stereo one may sound better.

 

[Audio-Me]

I don't trust mp3 encoding's accuracy on when to decide both channels are the same, infact I refuse to believe that they are ever both the same with an exception to electronic music. The though of joint stereo makes me sick, I can't help but think you lose all kinds of fidelity in using it. I doubt the "engineers" know much about audio quality, they just base everything on paper.

 

[blessingx]

Quote:

Originally posted by Audio&Me I don't trust mp3 encoding's accuracy on when to decide both channels are the same, infact I refuse to believe that they are ever both the same with an exception to electronic music. The though of joint stereo makes me sick, I can't help but think you lose all kinds of fidelity in using it. I doubt the "engineers" know much about audio quality, they just base everything on paper.

Why trust compression at all then? Just curious.