Do you have the P-Rails standard or hot version? If you have the hot version, then that is your problem. It can be very dark sounding with those 2 A8 mags. Replace at least the P-90 A8 with an A5 or even an A4 and you should be good to go (assuming that you have it mounted with the rail coil toward the bridge). If it's still too dark, replace the rail coil's A8 with an A5.