I just wired up mu audition AV5.1k amp in my car including the audison VCRA sub control knob. It doesn't seem to be doing anything as I adjust it. I am running the amp off of a Pioneer AVH-P6600DVD, all three pre outs are being used, fronts to the tweets, rear o the 6.5's and the sub outs to the sub channel. I don't know it there is a setting on the HU that is wrong or if its an issue with the VCRA?