Yeah the back wasn't all that great until I put an amp in, now they are as loud as the front, with gain/crossover adjustments. My speakers sound so awesome with rock music, but rattles too much with hip-hop.
Actually now that I think about it, the sub is a good idea in a convert. When I was driving with the top down the other day, all that bass I have with the top up isn't there as much with the top down (sound wise off course, the door still shakes the same), so a sub may be in my future soon, but I think I'd get one of those that I can put under the passenger seat.
Also, if you have an iphone or ipod touch there is a nice app called 10 Band EQ that is great for MP3s. Wish it worked with Pandora but no such luck. With that, you can adjust your sound exactly to your liking. It is the best EQ app for the iphone/ipod and I tried them all. Both my bass and treble on the desk are flat and the EQ does it all. I had been so close to buying an EQ to put in the trunk but glad I was able to save 400 bucks with this great app. There is also a good bass testing song called can U hear me by Bass Mekanik that you can get for a buck on Amazon to adjust your bass to its full potential without distortion.
2011 Mustang Convertible Kona Blue - FRPP Sport Axleback - Bama 93R - Blackout Panel - Tri-Bar Valve Caps - Airaid CAI - 4x JL Audio C2-570x - Alpine MRP-F300 Amp - Speaker Sound Dampening - 27% tint all around.
In the future: Kona Mirror Covers, Boss 302 Suede Steering Wheel, Possible Mono amp/Sub.