can some one help me fix the engine noise after i install amp

[HoOLiGaN]

hey all iv tried everything in the book the noise just makes me mad all the time .
iv done the RCA behind the HU to the ground it helped but  i still hear . not fixed the problem .
can some one help me with some ideas .
iv checked other HU too same noise iv chnaged to better RCA same noise iv checked every ground seems good