Wow? if the cable loop will cause noise? this noise is the same as my engine rpm.. the more rpm the higher the pitch.. btw interesting fact since i rolled/loop together my rca cable from HU to Preamp.. i'll try too unloop it and post the result here..

Thanks for your advice 
I already use spitfire spark cable.. so i dont think thats the problem.. my deduction either the RCA cable/grounding/alternater since the noise follow my engine RPM..

BTW thanks for ypur advice will post some result soon.. I'll let u guys know tomorow.. will take off my HU and rewire once again