CD-MAX is a anti-reflect product.
Used to clean up the CD, it cancels the parasite laser diffraction that are responsible for the wrong information the error calculator has to treat. The error calculator of a CD player recreates a signal which is close to the original one, but in a lower resolution; 14 bits instaed of 16 bits. By reducing the errors while reading, CD-MAX gives you a higher rate of 16bits sounds, that's to say the "real" sound, actually contained on the disk.
This phenomene improves the details of the low level sounds, increases the dynamic of transitions, a superior brightness in the bass. It lowers the hardness and respects the timber better, so, generaly speaking, gives more music in the music.