Hello My wife drives a signum. He should now get a 2channel power amplifier and a bass box. The power amplifier should be connected to the existing factory radio with the help of a high-low adapter. As everything is connected is clear to me, but I have concerns in one thing. If I have a bass box in it makes sense to turn the bass on the speakers down the radio because the LS can play louder without bass. But since the power amplifier with the HighLow adapter parallel I turn down the bass at the input of the amp at two LS outputs. Can I turn it up again at the power stage, so that the box can play enough bass? Because if no bass signal arrives at the amp, is there no longer to amplify, or do I see this wrong? So far I only installed systems that were connected via the preamp outputs, the problem is not there.