I have the AVIC N1, and have interior speakers amped, also a sub amped. I have a squealing, and sometimes burping sound, when engine is off or on.(sound is extrmely loud)likeit might wreck the new speakers. After this problem i made sure all my RCA's are ran away from the power lead and made sure everything was grounded right. I tryed grounding the RCA's at the amp and at the headunit. It helped to cut the noise in half but its still very loud! I hooked up a alternate headunit (alpine) and the sound was perfect! I dont understand, it has to be the RCA wiring harness of the AVIC N1 or inside the headunit. Thats what i narrowed it down too. Please help! I just spent $1000.00 in new interior speakers and they work with my old headunit but not the N1!