Jvc Nx F3

I have a JVC NX-F3 for couple of months now. It is a great performer & I am happy with this system, however there are few things to complain about: First of all you hear noise from the speakers while there is a CD / DVD in the unit playing, It is like the noise you would hear from high speed rotation of the disk. Although wires are connected to the main unit through color coded sockets, it seems as if connection is not fixed & steady, because if you move the end of wires near the sockets, sound from speakers changes. this was really disappointing! Also treble setting & surround speakers volume doesn''''t nearly affect the sound at all ! I would appreciate other readers comments about above issues. Thanks for your guidance.