Need help from the audio gurus

digitalink · 06-19-2016, 07:34 PM

I’m in desperate need of assistance from some of the audio gurus on this board…

I drive a 2007 E92 335i with idrive and the Logic 7 audio system. About a week ago, periodic audio noise started emitting when coming to a stop or accelerating from a stop (maybe when the vehicle is experiencing the most shift in force). It is hard to describe the sound, but it is to a popping/interference you would hear when your headphones are plugged in all the way. I immediately thought my phone wasn’t connected properly to the AUX cable, but that didn’t appear to be the case.

I changed the input to FM radio and the problem continued. When I’m driving normal, everything is clear. Even bumps in the road don't seem to cause a problem. Then I noticed something weird… Even with the radio powered off, when I turn the car off, I can hear faint feedback/popping from the tweeters in the door. I know when the car is “awake” the speakers are active for alarm alerts and in fact have heard the feedback interrupt the seatbelt chime.

I’m no longer covered under warranty and for obvious reasons would like to avoid a trip to the dealership. While I am mechanically inclined, I don’t even know where to begin here. BMW electrical systems are complicated to say the least. I’m leaning towards a ground issue or some type of loose optical cable, but where would I look? Could a fuse be the culprit? I checked the amp in the trunk and found no evidence of water damage.

I did find similar situations here on the board. One looked like it was defective HU for 2009+ making fax machine noises and I think the other was for a non i-drive so all the cables were connected directly to the back of the head unit. I'm not sure where to look for cables. I really appreciate any advice. I need my music!

cdgatti · 06-20-2016, 06:51 PM

I think others here have said this issue is caused by loose wiring at the head unit and also a defective head unit. You could remove head unit and secure all wire connections. If that isn't it, you may need a new head unit.

digitalink · 06-29-2016, 08:38 PM

Can someone who has experience with the idrive setup confirm for me where I should check for the loose wiring? Would I look behind the disk and navigation disk tray's, behind the nav screen, or somewhere else altogether?

As I mentioned in my OP I can the static noise faintly in my tweeters even with the radio off. So I'm not sure if it would be a "head unit" issue or something else that is wire to the audio system.

06-19-2016, 07:34 PM	#1
digitalink New Member 0 Rep 16 Posts Drives: BMW M4 Join Date: Jul 2013 Location: United States iTrader: (0)	Need help from the audio gurus I’m in desperate need of assistance from some of the audio gurus on this board… I drive a 2007 E92 335i with idrive and the Logic 7 audio system. About a week ago, periodic audio noise started emitting when coming to a stop or accelerating from a stop (maybe when the vehicle is experiencing the most shift in force). It is hard to describe the sound, but it is to a popping/interference you would hear when your headphones are plugged in all the way. I immediately thought my phone wasn’t connected properly to the AUX cable, but that didn’t appear to be the case. I changed the input to FM radio and the problem continued. When I’m driving normal, everything is clear. Even bumps in the road don't seem to cause a problem. Then I noticed something weird… Even with the radio powered off, when I turn the car off, I can hear faint feedback/popping from the tweeters in the door. I know when the car is “awake” the speakers are active for alarm alerts and in fact have heard the feedback interrupt the seatbelt chime. I’m no longer covered under warranty and for obvious reasons would like to avoid a trip to the dealership. While I am mechanically inclined, I don’t even know where to begin here. BMW electrical systems are complicated to say the least. I’m leaning towards a ground issue or some type of loose optical cable, but where would I look? Could a fuse be the culprit? I checked the amp in the trunk and found no evidence of water damage. I did find similar situations here on the board. One looked like it was defective HU for 2009+ making fax machine noises and I think the other was for a non i-drive so all the cables were connected directly to the back of the head unit. I'm not sure where to look for cables. I really appreciate any advice. I need my music!
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06-20-2016, 06:51 PM	#2
cdgatti Colonel 255 Rep 2,547 Posts Drives: e90 328i Join Date: May 2011 Location: KY iTrader: (4)	I think others here have said this issue is caused by loose wiring at the head unit and also a defective head unit. You could remove head unit and secure all wire connections. If that isn't it, you may need a new head unit. __________________ OEM Black grill and Blackline tails - LCI halogens with Lux V2 coded as DRL - 3M Crystalline - BMS PBX - OEM Euro Airbox with K&N - Hardwired CTEK - Bilstein B6 w/OEM springs and SP perches - Conti DWS06 - HiFi-Helix DSP - JLAudio HD/XD-Morel - CD changer trim - AE optical out
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06-29-2016, 08:38 PM	#3
digitalink New Member 0 Rep 16 Posts Drives: BMW M4 Join Date: Jul 2013 Location: United States iTrader: (0)	Can someone who has experience with the idrive setup confirm for me where I should check for the loose wiring? Would I look behind the disk and navigation disk tray's, behind the nav screen, or somewhere else altogether? As I mentioned in my OP I can the static noise faintly in my tweeters even with the radio off. So I'm not sure if it would be a "head unit" issue or something else that is wire to the audio system.
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