I am the happy owners of a BT3900U bluetooth car stereo unit and have connected 4 speakers via the car adaptor. What I am wondering is whether I can also connect a modest subwoofer without losing the rear speaker performance as it is a 4 channel amplifier. Some international versions of this unit seem to have an extra subwoofer output but the UK version is a little different with just two sets of RCA sockets for front and REAR/Subwoofer. I am trying to understand the installation diagram, which might show that any subwoofer connected to these would have to be an active type with a separate amp, but I am not at all sure. Help would be appreciated!
