I have Mazda 121 (2002) and bought Sony MEX 5200BT + Crunch 80w coax speakers. I put them on the front door and basically until 75% volume it is all fine. After 75% volume it all sounds pretty bad, some noises come out and the sond is actually barely recognizable. On <75% volume, the sound is better and louder than the previous system, but am asking myself what is going wrong after the 75% volume