Can someone explain what this sound might be just installed a new magura discs and still make the same noise.i have a cube stereo tm the disc size is 203mm i tought because the old one was bent,the new one wouldnt squeel or whistle as i would say.

Sounds like the new one has a small bend to it. You can straighten it out simply enough using a crescent wrench. spin the wheel, see at what point it is touching and lightly bend that spot the opposite direction of contact….lightly is the key word here, it does not take much to align it. Also make sure the jaws of the wrench that come in contact with the rotor are clean or place a towel of some sort between the jaws and the rotor, paper towel will usually work fine for this.