I have a question about my DSP unit that I installed. I have a constant low-level whining through all of the speakers and you can hear the interior lights dim as well as whenever anything electrical is activated. I have the Harmann/Becker amp; I soldered ALL of my connections, including at the navi, and removed the wires from the amp plug that are not in use. The amp is not blown and sounds awesome. I am just wondering if anyone else has had the same problem. I have tried the in-line noise cancelling boxes that you tie into the power line on both s-contact lines at the navi and the amp; I have yet to try them on the constant power. Any thoughts?