I upgraded the front and sound bar speakers to the Boston Acoustics from the Challenger and have been very happy with the sound but would like more bass. Has anybody upgraded the subwoofer using the existing enclosure and adding an amplifier in line such as the Rockford Fosgate pbr300? If so what speaker/amp combination did you use and how much of an improvement is there considering it's still a single 8'' sub?

 

I upgraded the sub with a 10" in the same enclosure, but it you don't want to do any fiberglass work or alter the existing sub box, you could try the 8" version of the RF Sub I used. It should drop right in and is dual 2 ohm just like your factory Infinity/Alpine.

Power it up with the outboard PBR300x1 if you want more punch.

P3SD2-8 8" Punch P3S Shallow 2-Ohm DVC Subwoofer.

 

This is what I did, I love them ( hyphonics amp