Hello, I had exchanged my original radio for an Android radio. Everything is running very well as far as possible. In order to amplify the bass, I bought the original subwoofer for under the driver’s seat. Built-in and connected with the cable installed for it. I wanted to test it with full anticipation and nothing happened. Does there have to be any additional changes on the radio? In most reports it says yes, connect and done! Can someone write something to me!? Thanks in advance. Greeting Steini