I have a BOSE car and I just changed my sub set up this monday, I used to have a Cerwin Vega 10" compact powered subwoofer - It was definitely OK and added some extra bass but I really wanted to feel it...
So I bought a 12" Powerbass Subwoofer / ported loaded enclosure combo a long with a Rockford Fosgate R500X1D mono amp - Birthsheet 622 watts @ 2ohms, but the sub is 4ohms. (but that means I can upgrade in the future)
Sub is rated at 275w RMS and the amp is rated at 300w RMS @ 4ohms so it's a perfect combo
I did my best to have a super clean set up... no wires visible whatsoever
and OMG... going from stock BOSE bass to the 10" Cerwin Vega was ok... but then going from that to this 12" ported sub/amp combo is insane
I can FEEL the bass and it's so clean, and it's still breaking in!
I'm going to wait until the sub breaks in before I tune it, running it at moderate gain
I mounted the amp to the back of the seat, it has some parts that are sheetmetal, the screw holes lined up perfectly to the parts that had sheetmetal on the seat. Drilled some holes and screwed it on.
The holes are so small you can't even see them, so I don't have to worry about it looking ugly if I ever take it off (it hurt my soul when i drilled that first hole though)
And for the sub I went to walmart and bought 2 sets of non-slip rubber feet meant for furniture and put them under the sub and WOW it doesn't move at all, worked waaay better than I thought
But it also helps that the sub is like 30 something pounds haha
I initially thought I was going to have to drill and mount it or tie it with ugly bungee cords
The best thing is since I have the amp mounted separately I can simply disconnect the speaker terminals from the sub and take it out if I ever need too, or even move it around the trunk and still fold the seats down
The trunk has so much space I'm amazed
But now this thing puts out so much deep clean bass the door woofers are useless...
I'm thinking about getting ANOTHER amp.. 2 channel.. and running some full range speakers instead... but then I would have to figure out how to run speaker wire to the inside of the doors through the factory rubber grommet and how to create some kind of mount for the speakers to fit in the 8" speaker hole