subwoofer problems

[atanner]

i got 2 12 inch mtx. they are plugged in all good but i turn them on and they move to music but no bass seems to come oout. but if i only ahve one 12 plugged in it pounds and sounds great.

reason for this anyone .?

[Installer4life]

Well if you haven't figured it out by now you have one subwoofer out of phase. Swap the positive and negative wire on only one subwoofer...