I am running a kicker 1500.1 and a dual 1 ohm 15'' bl from my factory nav/cd player in 05 escalade using a audio control epicenter plus and was told that my kicker amp does NOT have subsonic filtering for the sub PLEASE what do I do? Also my box is 4.00ft.^3, port area 56.00in.^2, and tuned at 30hz

Get another amp with a variable sub sonic filter, watch what music you play that it doesnt dip below box tuning or get an external (in-line) sub sonic filter/high pass filter for your rca's.

It should have a fixed subsonic filter at like 25hz. Kicker amps are like that. You should turn it on.

It should have a subsonic filter...just fixed at 25Hz. I have the 1000.1 on a 15 BL. My current box is daily tuned to 34 and for comps it is tuned to 42. I have only found a couple songs with the aero ports tuned to the 42 Hz that the sub can't handle. I think FMOD has a filter.

So does this mean I do need a inline subsonic filter if so which would you recommend or is the 25hz sufficient from the amp itself? I also understand you want all of the bass boosters down on everything and the gain needs to be adjusted on the amp to match what the epicenter is putting out for volts is this correct?

I also have a zx1500.1 with a fixed subsonic filter. My box is tuned right around 32hz and I play a wide array of music and have never had an issue. With that said it still depends on what you tell the sub to do, push it below tuning hard and you will have problems.