this is nto a shity subwoofer. PM me if you want to sell it...with price shipped to 28540i will tell you what u do with them... You own a boat?
If so u got a new boat ancor
thats what i got told to do with some shity 15 i had
pretty sure it has 3 inch coilspretty sure this has a 3.5" coil for the 12" version, 3" for the 10", and 4" for the 15".
http://www.diamondaudio.com/manuals/hex_pro_subwoofer_manual-2008.pdf
I would trust the manual over sonic electronicspretty sure it has 3 inch coilshttp://www.sonicelectronix.com/item_5533_Diamond+Audio+D912D2.html