[carstereopro]

Originally Posted by 92SCHNITZER

You are outputting high-power out of your alpine headunit into the lowlevel input of the factory amp. It is only a matter of time if you listen loudly then you probably blew the input stage of the factory amplifier. This is a really easy fix just bypass it.

Yes, there is a remote possibility.

But BMW's OEM Amplifier is designed to take a very high voltage pre-amp level input.

Installing an aftermarket radio through the pre-out section connected with the factory amplifier tends to limit the volume level that can be achieved. If an 8V aftermarket headunit were being used, this is not an issue (a waste if a nice headunit, but not a voltage issue).

The output voltage of the OEM headunit is somewhere between pre-out level and speaker level. As long as a fully clipped signal never gets sent to the stock OEM amp, he will likely never have an issue.

If he were to run the aftermarket headunit at full volume for prolonged periods, which would eventually damage both the OEM amp and headunit, he would likely blow the speakers as well. (not to mention the fact that above 3/4 volume the distortion, clipping, and popping would be unbearable)