Ive got this dillemma on setting the crossver potentiometer on my PDX-5s mono channel. Im using an Alpine 9887 deck and it used to be the crossovers on the HU thats doing all the work. But since I cannot turn off the xover on the PDX for the sub, im stuck using the analog. Ive already set the low xover on the Alpine HU to flat, so that all the processing for the sub is being done by the xover on the amp. Now my question is, how do i set this accurately? The numbers around the pot just dont cut it for me. How can set this thing accurately? I was thinking of using TrueRTA as a tool but other more convenient ways might be out there. Hope somebody can help!