I recently bought Audiobahn AW1251T Subwoofers with Bandpass Enclosure & a Audiobahn A2301T Amplifier and i have two questions. How much knowledge do you need to have in order to hook up a sub system? Can places like Bestbuy, Circuit City do it for me even though i didn't buy it from them (i know i'll have to pay? If so, how much do they charge?