Hey baco99 -
There is a difference in size between 5x7 and 6x8. Some speaker companies may call their speakers 5x7/6x8, but if you measure them, you'll find that they're usually 5x7. Next time you're at a car stereo store, compare the Pioneer 6x8 with anyone else's 5x7.
Also, don't assume that a 6x8 will sound better than a 5x7. If you need convincing, listen to a Pioneer 6x8 then an Infinity Kappa 5x7.
Just an FYI.
