Difficulty converting an MP3

[yukichigai]

okay, I'm trying to convert an AC3 over to MP3 with BeSweet. In an effort to conserve space I decided to make it a monoral MP3, so that I could get the same sound quality (save for the stereo aspect) for half the space. Except for some reason that isn't what happens. I've encoded it as a 40kbps mono mp3 and an 80kbps stereo mp3 and for some reason the 80kbps sounds obviously better. I mean one would think with only half the sound channels to deal with the 40kpbs version would be identical, but apparantly I'm wrong. Any ideas on how to make it sound... right?

 

[AkumaBao]

It doesn't quite work that way. You are losing a lot of ranges and data blocks. Providing stereo isn't going to really make up for 1/2 of the data loss from dropping the encoding. I'm not even sure it really saves that much room to drop to mono. Try doing 80KBps stereo and mono on the same song, and check your results. That's a pretty depeciated sound to begin with. Most MP3s are encoded at 128K, but some even go as high as 256K. Did you ever think of converting to Ogg Vorbis instead?

 

[yukichigai]

I'm encoding for the purposes of making an xvid movie, and at the moment I'm not quite up to making an OGM. (syncing the audio can be incredibly difficult) Besides, BeSweet refuses to do Ogg mono... though I doubt the monoral bit matters with what you've told me.

Hrm... better stop the stuff from encoding eh?

 

[CTho9305]

FWIW, changing from one lossy format to another will almost always sound relatively bad. AC3 is throwing away certain parts of the sound and slightly changing others. Then, when you go to MP3, it throws away different parts of the sound and slighting changing different parts. The result: a LOT of lost or changed data. I've seen DivXs / Xvids with AC3 before... why not leave it?

56kbps MP3 is supposed to sound something like radio, and 32kbps more like a phone.