just wondering if 6x9 produce better sound than can speakers?

what are "can speakers" and what type of enclosure are the 6x9s going to be in?

Assuming proper amping and such, 6x9's will be louder than 5.25's (and 6.5's), so if you are looking for speakers on a tower, probably a better bet to go with 6x9's.

There was a big debate about six months ago between 6 - 6.5s vs. 4 - 6x9s. I have always said that 4 - 6x9s is a pretty good tower solution but there seemed to be lots of support for the 6 - 6.5 solution. Although the four 6x9 is easier to power and wire, that alone tips the scale toward that solution. I am assuming that you meant 6.5" not 5.5", I have the 5.5" cans to be kind of a "for looks only" thing.