Thanks for the reply.
I have CDex and use it for mass mp3 converting.
But in my experience, mp3 sound quality of Sonar X2 is better than CDex's highest quality setting. So I'm looking for the method how to convert mass mp3 in X2.
My mp3 setting in X2 is :
44100, 16bit, no dither, fast bounce, 64bit precision(don't know if it applys to mp3 though), 320Kb, max quality and joint stereo(sounds better than stereo).
CDex setting is :
Lame MP3 encoder 3.99 MMX, MPEG1, 320K, stereo(sounds worse with J-stereo), 44100, and --alt-preset CBR.
In personal, mp3 quality of Cubase is worse than these two,
so mp3 quality rank is 1) X2, 2) CDex, 3)Cubase .
J