Hello, I would like to try out how it sounds, if I use my subwoofer without an amplifier.–> please don’t “sound can forget anyway…” etc. Comments. Is only a test :-)The reason is quite simple: At the moment, the installation of my audio system by a specialist workshop is simply too expensive for me. Maybe in the summer, if I am liquid again… But until then, I don’t want to do without a little more bass sound in my Vectra C 2.2 GTS. The front system in the car is so reasonably OK. I would like to put the subwoofer in the trunk and connect to the cables of the two HINTEREN loudspeakers (back doors). So I would have a direct access to the radio (NCDC 2013) and could test the subwoofer by means of “fader”. How do I best get a cable from the trunk to the entrances of the two speakers of the rear doors? And… how do I then connect the two cables (from re. + li. LS) together?