Car Stereos: subwoofers, load impedance, mono amps

Question
I have two 12 inch boston g1s on a 1000 watt kenwood 2 channel amp and they pound but i jus got a 12 inch jl speaker and i hooked it up to my amp and it sounds like crap when there all hooked up but when i unhooked the jl there sounded fine again. they looked like there were workin real good but the sound wasnt right at all

Answer
Hi JD,

As a general rule, if you experience a serious loss of bass output when you connect an additional subwoofer, the first thing to try is reversing the (+) and (-) connections on the sub.  If the new sub is connected with the polarity opposite that of the other subs, it can have a huge effect on the overall bass output.

With that said, I don't know of any good way to connect three subwoofers to a typical 2-channel amp.  Usually, multiple subwoofer systems are best used with mono amps, which can handle a lower load impedance than a 2-channel amp wired in "bridged" mode.  Go ahead and try changing the sub's polarity; I think that will bring back your bass output, but you might find that your amplifier overheats, blows fuses, or begins to shut down for protection.  If that happens, you'll need to get rid of the extra sub, or switch to an amp that can handle the lower load impedance.

Hope this helps!

Brian