My set up sounds perfect!

Kenwood BT system.
Kenwood KMR-D562BT Marine CD receiver at Crutchfield.com

Infinity Speaker upgrade from Best buy.
Infinity Primus 612" 2Way Component Speakers with Plus One Woofer Cones Pair Black PR6500CS - Best Buy

200hz capacitors 100 watt connected to door woofers found online.

Pyle dual coil Subs.
PyleŽ PLPW6D - 6.5" 600W Dual Voice Coil 4 Ohm Subwoofer

2 cans of 3M sound deadening undercoat spray for the doors.
3M 08883 Underseal Rubberized Undercoating Black


Now I got the sound system sounding awesome. Mid's and High's very clear and the subs are thumping hard when the bass is turned up! All on the stock amp!