does anyone know if these 6x9's are any good? i can get them for $70 shipped brand new in the box...or should i get different 6x9's...i have a RE SX15 in the trunk and am looking for something that will sound good with that sub...i only want treble out off these 6x9s...or should i get some other sized speakers, like 6 1/2's or something like that...what are some good brand speakers?