The bass in my Sony 3-way 6X9 speakers wont work

SOURCE: Sony XS-V1342A Coaxial Car Speaker

You amp has a low pass filter turned on. There should be a switch to turn it off on the amp, otherwise you need a different amp. Be careful, 600 watts is WAY over the v1342a's rated power of 45 watts rms. If you turn it up too loud, that amp will easily blow your speakers.

SOURCE: have hooked up a sonycdx-gt290 radio into a1993

The code for the wiring colors should be on the back of the radio. But, you can figure this out with one extra speaker on the bench (or floor board) The colors are in pairs = "gray - gray with stripe" The stripe will be the negative side of your speaker. So you will have a Gray pair, white pair, blue pair and green. Using one speaker on the floor or already mounted, hook it up to one pair of colored wires, lets start with gray. Now run the radio balance right then left, then fade front to back, to see which your speaker is hooked to. Make a note of which, then the next color run the balance right then left, then fade front to back, then the next so on and so forth. This way you will know which is which and you will have it written down for future reference when you move the radio into a new car. So if your gray pair has no sound on the left balance you know it is a right side speaker, then if it has no sound when faded to the front you know it is a rear speaker, so in that case Gray would be "right rear", Hope this helps Fixya up.