User Tips: 1.It is a normal phenomenon that FM product will have some noise because of the interference of the local radio signal.Find a vacant or non-interfered frequency and sync Onever device to that frequency for minimized static noise. 2.To achieve best audio quality,please set the volume on your phone or the device to maximum and then adjust the volume for your car stereo;you are not suggested to adjust volume of your car speaker to maximum (this will bring lot noise). 3.Suggest that RAM less than 32GB. larger than 32GB which may cause the abnormal reading. .