BMW Professional CD54

– One or more channels have failed. If all channels have failed, then the unit must be tested first to see if it is repairable.

– buzzing, squealing, rumbling sound from all speakers (not amplifier fault, but processor chip fault)

Amplifier Power/Wattage Upgrades And Repairs

The bonus of having this repair done, is that the sound will be improved. The usual power output is 15-20 watts per channel, and the after the modification, you will be running 5oRMS watts per channel.

Some cars are equipped with DSP Amplifier or Harmon Kardon Sound upgrades from factory. The Amp upgrade on the radios improves the overall quality on these units. Instead of a weak signal going into the DSP or HK amp, a much higher quality signal will be going in, and so improves the overall output of the amplifiers.

If you have the DSP system, that may be faulty, so please check out the DSP Repair Service for  more information.