I want to get my twin brother something decent this year for Christmas because he's really one of the most generous people know and really deserves to have something nice. He's got a 2006 R/T Charger with the upgraded Boston Acoustics sound system option and I'm looking into possibly getting him a decent quality sub & amp to compliment his system- the problem is I know there are a ton of genuine audiophiles on here and, to most of you, anything below $1000 is a waste of time. Unfortunately, I don't have that kind of money to spend, and I'm looking to keep it around $400 if that's at all possible. Any of your input is appreciated as always and just know I really know next to nothing about car audio but I'm doing my best to learn as I go.