The rear-end part of my 2-part Becker Mexico got corroded, and I had a company install a new Alpine radio up front. They tell me it's impossible to connect the "active base" powered amplifyer whoch drives the front door speakers. They tell me that they cannot connect the same speakers directly to the new radio because of impedence and ground problems. I seem to be stuck with 4 speakers, none of them doing the bass work. Anybody know better? ---mason