Ok, after thinking on this i might do this...
I have a dual 10 box at the house.
I have this amp: db Drive sp120.2
Spec are:
SPA120.2 Class AB technology
2 x 120 watts - 4 ohm @ 14.4
1 x 500 watts - 4 ohm bridged @ 14.4
2 x 240 watts - 2 ohm @ 14.4
So i am thinking on these subs:
http://dbdrive.net/html_english/speed_subwoofers.html
SPW10.2 10"
single 4 ohm voice coil
Max - 600 watts
RMS - 300 watts
Sensitivity - 85dB
Magnet - 50 oz.
Forget the 15Odb if i run the 240 watts, you think this will sound good?