Economical Upgrade of JBL Stereo?

[mader]

So I have the limited with the JBL and Nav. It includes the subwoofer in the rear gate.

It sounds fine. Not great, just fine. The subwoofer is pretty bad. It gets lost in the back. The system itself also doesn't generate full sound at the lower volumes, meaning, it sounds better at a high volume.

Anyway...What would you all recommend for an economical (say $500-$750) upgrade? I don't know much about amps speaker compatibility and those things.

Thanks.

[paolodoctolero]

you can check crutchfield.com and speak to an agent..they can help you with subwoofers and amplifiers compatibility..they can also suggest what subwoofer you want base on your budget..