when me and my friend first hooked up my CVX sub box i had him just connect my speaker wire to the terminals on the box, i said "i have the white wire as positive and the green wire as negative" on the box, he wired the pos from the amp to the neg on the box and the neg from the amp to the pos on the box, while the subs were wired correctly on the inside
it was like this for 2 months until i saw it when i moved my box... and it played fine the whole time.
so dont think wiring it backwords did anything