Combining Stereo and Mono?

[jeffoest]

I think I know the answer to this but I'm hoping to maybe be pleasantly surprised.....

Is it possible to combine a segment of one-channel mono and a segment of two-channel stereo into one mp3 file. ie. enjoy the better quality of mono for voice and stereo for music in the same podcast?

[speechless]

That's a neg, though some encoders will detect identical left and right channels and save space.

[ferg]

Jeff,

I believe that is effectively what "Joint Stereo" is supposed to do. When you encode in Joint Stereo, it detects when everything is "in the middle" and basically combines the two, and splits when necessary.

However, I've tooled around with JS, and found that the overall quality sounds worse than when I simply encode in plain old stereo.

I usually encode at 64kbps stereo, but I encoded our entire last cast in 64kbps mono. I think it sounds much better. There is definitely something lacking a bit on a couple of stereo intros/sweepers we have, and on music. The clarity is better, but stereo is, well, stereo. However, since 95% of the podcast is just speaking, I think I'm going to stick with mono, at least for now.

[jeffoest]

Thanks guys - I was wishful thinking ;-)

Ferg, I DID notice this in your last podcast (yea, I'm listening....) and in fact I went mono on our show 8 (not the last one). I was going to do it for show 9 but MY song sounded horrible going mono (I had these panned double-tracked guitars on most of the track and since I'm not a professional I suppose they were phasing all over the place in mono). However some of the other musical interludes, while not sounding as great, were certainly passable in mono.

I dream of optimizing for both some day ;-)

[Craig]

However, I've tooled around with JS, and found that the overall quality sounds worse than when I simply encode in plain old stereo.
What encoder were you using? This should work the way Jeff wants if the encoder has implemented it properly.

Craig

[ferg]

What encoder were you using? This should work the way Jeff wants if the encoder has implemented it properly.
Craig

I'm using the Sony mp3 encoder with SoundForge.
It was the first time I used it. I encoded at 64KBps JS and felt that it sounded, overall, not as good as the stereo 64kbps recording. The voices sounded very unnatural / digitized. I wasn't suggesting this is a symptom of joint stereo...I just wasn't happy with the results. I may need to tool with it some more.

[jeffoest]

Yea, It's good info to share but at the end of the day I've found that I just have to 'twiddle about' with various encoders and settings to find the best compromise between quality and size.

For what it's worth, I've been suprised at the quality of the Apple iTunes encoder. I also use Adobe Audition (various codec supports) and CDEx's LAME encoder (my favorite so far for very-high quality compression)...

[Craig]

I use LAME from the command line.

Craig

[jeffoest]

Craig - YOU'RE the man! LOL Actually I believe that CDEx Lame is the sams as comand line LAME but with an interface.... which people like me desperately need ;-)

I use LAME from the command line.

Craig