subs won't pound

I recently had a system installed in my 1991 crown vic. Replaced back speakers, put in two 12" JL audio subs and pioneer amp in trunk. Had them for about a week before I swapped out one of the subs( they're used and the one had worn out). The system sounded awesome until I changed the sub. Now the subs won't pound. They're getting power as they do still beat but it's nowhere near the sound that they had before. They can barely be heard in the cab, even when turned up relatively high. I suspect a connection or wire has come loose but I don't know where to look. Any ideas as to what would cause them to beat but not POUND would be greatly appreciated.

make sure the polarity is correct. If the woofers are out of phase it could do what you are describing

I too vote for an out of phase driver.  Reverse the positive and negative wires of ONE of the woofers.  Does the bass level increase?

i am an idiot wrote: I too vote for an out of phase driver.  Reverse the positive and negative wires of ONE of the woofers.  Does the bass level increase?

Agreed. If your subs are side by side and the polarity is reversed on one of the subs there will be destructive interference. If your system pounded before and is now a whisper compared to what it was before, then this is most likely your problem.MECP Advanced

Make your life easier and buy a DMM.

Wow. Easy fix. Thanks guys I once again have a portabe defribillator in my trunk!!

LOL. Reversed polarity is awesome. I once saw a pair of twelves that would hit a 145 on the TL hit a 110 because of it... laughed for days... Once I even purposefully wired up a buddy's subs wrong to mess with him...1 Panasonic HU

1 Power Acoustic Amp (sorry)

1 Amazing Box

3 Kicker CVR15s

1 Termlab

36 Hertz

139.5 Decibels

1 Big grin.