Ok I have 2 10 inch kicker l7s with a Rockville 4000 watt amp all brand new I am using a kicker high-low pass of the rear speakers to get signal but when I turn on my car bass is hitting hard to about 5 or 6 seconds then shuts off and plays just fine. This is in a 09 Infiniti g37s with Bose and factory amps. I have had this set up with a single 12 inch and a different amp no problem