Why Does the Turn Signal Sound Get Louder After BMW Audio System Modification?
3 Answers
After modifying the audio system in a BMW, the turn signal sound becoming too loud may be due to excessive DSP gain. Reasons for the louder turn signal sound: This is caused by improper adjustment of the output signal between the added DSP amplifier and the head unit during the modification process. Solutions: 1. Appropriately reduce the DSP power, setting it to achieve optimal effect when the volume energy bar is at 60%. If adjusting the DSP power doesn't work, it's necessary to visit a professional repair facility for RTA debugging using specialized software. 2. Perform precise settings for crossover, delay, EQ, operating points, etc., to ensure the head unit, amplifier, speakers, and vehicle's acoustic environment work in harmony.
After I upgraded my audio system last time, the turn signal sound also became extremely loud. At first, I thought it was because the speaker power had increased, so the notification sounds got louder too. Later, I asked a friend at the modification shop and found out that BMW's design actually ties these system notification sounds to the audio speakers. They readjusted the amplifier's audio input lines for me, routing the notification sound signal to an independent channel instead of the main power-amplified channel, and it immediately returned to normal. If you don’t know how to do it yourself, it’s safest to go directly to a modification shop and have them use professional equipment to check the wiring connections, as the control module wiring harness under the steering wheel is quite complex. This issue is particularly common after upgrading to Harman Kardon or Bowers & Wilkins audio systems.
After installing the Bowers & Wilkins audio system in my 5 Series, the turn signal sound suddenly became uncomfortably loud. Through troubleshooting, I suspect it might be caused by the programming modifications. During the modification, the vehicle system was reset using a computer, which likely messed up the 'System Alert Volume' parameter in the sound settings. There's a hidden settings menu in the iDrive screen—enter engineering mode by holding the iDrive knob for 10 seconds, then locate the 'Chime Volume' option in the audio settings and reset it to default. Also, check the vehicle configuration parameters to ensure the modification shop didn't accidentally enable the enhanced alert sound feature for sport mode. BMW's electronic systems often have these minor quirks—if you can't fix it yourself, it's best to visit a dealership for a programming reset.
