Aeroworks

I have a new Fosgate P600x4 amp and performed the c.l.e.a.n setup following the instructions. This amp is for the mids/highs and is set to high pass.When the gain is setup per the instructions I get a loud hiss from my speakers. Lowering the gain to half or lower makes it almost in audible but the c.l.e.a.n. setup has me put the gain almost 3/4 full. Is this normal? I can turn the gain down to eliminate the hiss but whats the point of the clean setup if it introduces a constant hiss? The hiss is a constant steady hiss. does not change with car on/off parked or driving. Some notes and observations during install:-When rca jacks are unplugged from amp,hiss does not go away-Using OEM uconnect stereo (jeep)-At full volume, input clip light never lights up-Using an audio control lc7 for line level converter-C.L.E.A.N setup using the 1khz 0db audio track