Audio Systems: subwoofers not working properly., dual voice coil, input level control

Question
I have a pair of Lanzar MAXPRO12D subwoofers in my car right now.  When i originally had them wired both worked the same but now my left subwoofers doesn't pound as hard.  It puts out bass but not as much as the right one does.  Could you tell me what could cause this problem.

Answer
Are you driving them with separate amps? If so, check the gain settings of each amp input level control.

Are they in parallel?  If so, check the wiring to each speaker.

Are you driving them in series?  Check the wiring for shorts.

Are they in stereo? If so, the program material may have more energy in one channel than in another.

Are they dual voice coil units?  If so, see if one is in series and the other in parallel.  Or if one voice coil is burned out.


Hope this helps. If you need more help, give me the details of the amp and the connection scheme you are using.