The wire with the trace (white with black stripe) is USUALLY the negative, and with the TRX, im pretty sure that is the case, its been a while, so im not 100% sure, easiest way to test is to hook the wires up, but not to the speaker, turn the radio on, the proceed to touch each wire to the "correct" terminal on the speaker, ie: grey with trace to neg, solid grey to pos, see how they sound, then reverse them, if the sound better, thats how they should be connected, if not, leave them as they were.