I had a kick ass Alpine S-12 once, then sold it to reclaim trunk space and used my amp to power my front speakers, then missed the bass so picked up a shitty $100 box and 10" woofer combo on sale.

At first it was very, very acceptable. I had the gain on the amp turned down to 1/3rd, but over the last few months I've had to crank it up and up and up, and now I'm almost at full gain, and full sub-out on the head unit (seperate subout and control). The thump is gone.

What's dying here? Do woofers slowly turn to crap, or is it the amp? Amp is a Phoenix Gold QX-2180 (180 watts at 4ohm bridged), couldn't tell you what the woofer is. I think it's some MTX bottom of the barrel, probably used as the in-store demo before it got picked up by me.

Should I spring some bucks and get another sub?