I bought a Kkmoon 7" Blue tooth stereo in June fitted it about a month later I found that the reception was very poor and the BT had a time delay, so i changed the Arial and made sure all the earths were good which improved things slightly. Since then the BT delay as now turned into a load buzz when you try to answer a call I have re-check all the settings but still have the problem, what can do to rectify these faults.