I am going this afternoon to get a sub and amp installed and need the boards advice. I have narrowed down my selection to two brands and two size woofers. The 1st is an xtant 10 or 12 with an xtant amp(Personally I dont know anything about this brand but have heard it is good. The second is a jl audio 10 or 12 with a jl amp. Which brand would you go with and which size woofer? This is the only mod I want to do to the sound system and want to make sure the stock bose is not "overpowered " by the woofer. Thanks

 

Personally I would go with an Xtant amp and Eclipse Aluminum sub(12'). If that is too much go Xtant amp, JL sub 10w3 D2.
The only reason I mention Eclipse 12 is it will sound like a 10 during fast repeated bass notes but can go deep like a 12.