Ok.. i've searched and searched and searched.. so far all i can find is that the subwoofer is apparently a DVC sub. Has anyone upgraded the subwoofer? Do you know what impedance the subwoofer is? All i can find is people claiming to have upgraded to a 10" subwoofer, but no pics or proof.. i don't want to tear the subwoofer out until i have a new one to install, and i don't want to order a new one till i know what i need. Thank you in advance...