Help: Constant noise from speakers

roundle · 04-17-2014, 11:59 PM

Hi All,

My stock MY2011 328iT is driving me crazy. The base professional radio has a constant, high-pitched "frequency noise" coming from the speakers, even when the the radio is off. the noise starts when I unlock the doors and gets louder after I put the key in the ignition.

Here's a video:

Head unit? Ground issue? Capacitor? How should I troubleshoot???

roundle · 04-19-2014, 02:26 PM

Turns out that this was caused by a loose optical cable connection in the rear of my “Professional” head unit. The solution was to bend the head unit’s casing a bit so that the female connector (the bit that’s built into the head unit) stopped moving around.

See pics of my ingenious solution below.

1st image: up-side-down fuse box: Pulling the blue 15 at the bottom middle (well, top) was the only fuse that stopped the horrible buzzing sound. This was the fuse for the head unit.

2nd image: After pulling out the HVAC control and the cheap-o head unit, here's what you see. Note the funk sock around the cable that is attached to the antenna cable.

3rd image: WTF is this sock? Do I own a 1980s Alfa?

4th image: Here's what under the sock. WTF is this for, sat radio?

5th image: Here's the harness that plugs into the back of the head unit. Note the optical connections in holes 1 & 2

6th image: Here's a copy of the Professional radio (the cheap one)

7th image: Here's the female bit where the harness plugs in to. This is the bit that had play. When I wiggled this, I could modulate horrible buzzing sound. When I pushed the female bit in, the buzzing stopped.

8th image: My solution: Wrench on the head unit's tabs that hold the female bits of the harness to the head unit. i.e. bend them so they press/hold the stuff in place

9th image: WTF is this doing in my car? My car does not have Bluetooth. I assume that BMW added this box to enable my iPod/USB. Totally hilarious that they added this cost/weight/complexity for a y-Cable that would become outdated and unusable within 24 months.

taibanl · 04-19-2014, 04:26 PM

Thats the mulf-hi: yes, for ipod/usb, yes you can use it to add bluetooth for $50.

Zeke3 · 08-17-2014, 01:41 PM

This noise has been driving me crazy for almost a year. I didn't have to bend anything, and I don't have optical cables in my harness. Just reseating seemed to fix it. Thanks for the DIY!

roundle · 08-17-2014, 02:39 PM

Quote:

Originally Posted by Zeke3

This noise has been driving me crazy for almost a year. I didn't have to bend anything, and I don't have optical cables in my harness. Just reseating seemed to fix it. Thanks for the DIY!

Nice to hear it worked out.

What exactly did you have to re-seat, the blue connection?

Zeke3 · 11-22-2014, 11:50 AM

Yes, the large harness. It is blue on yours, but black on mine. Also to give an update, the noise came back as soon as the weather turned cold in Ohio. This time I went ahead and bent the tabs like you, so hope it works.

gamesfrager · 03-23-2018, 09:24 PM

I was excited to find this thread, I thought it is going to solve my issue which you can hear https://drive.google.com/file/d/1PMa...w?usp=drivesdk
after 45 min struggling to take the heater panel, disconnected it, removed the radio and unplugged the big black harness, I replugged it back and unlocked the car (the noise usually comes after the locking/unkocking), it was still there, but now an added loud pop, like a heart beat is also heard.
I didn't bend the tabs, it was getting dark and cold. I'll do that tomorrow.

From this new loud pop, I'm 90% sure it is something to do with this connector.
I'll post my update tomorrow.

gamesfrager · 03-26-2018, 09:13 PM

Well, sad to say nothing I can do to eliminate this noise.
Replacing the radio would be super expensive.
Oh well, I tried.

ctuna · 03-26-2018, 09:24 PM

Replacing the Radio will not necessarily be super expensive if you
can do it yourself.

Also
http://www.e90post.com/forums/showthread.php?t=1036190

The fiber optics are displayed in the 5th picture inside the radio connector on the lower right. It impossible for a Mulf or TCU module to work without fiberoptics.

gamesfrager · 03-26-2018, 09:28 PM

I guess, but still money spent.
I did mention it to the dealer while the car was still under warranty. So it is on records.

I'll bring it up again since the noise is more noticable now.

watchout-everyone · 12-27-2023, 08:23 PM

Thank you. This post helped me remove the noise. Condition i noticed was before fixing was

- The car would make this sound from the moment it gets turned on in anyway (including initial unlocking the car)
- The sound would stay on for like 10 seconds even after turning off + me exiting the car physically + and locking the car

I just took it out and replugged in everything the sound is gone like 95%.

04-17-2014, 11:59 PM	#1
roundle EXPAT 65 Rep 889 Posts Drives: 18 VW GTI;18 CX9;11 E91 N52 Join Date: Apr 2010 Location: USA iTrader: (0)	Help: Constant noise from speakers Hi All, My stock MY2011 328iT is driving me crazy. The base professional radio has a constant, high-pitched "frequency noise" coming from the speakers, even when the the radio is off. the noise starts when I unlock the doors and gets louder after I put the key in the ignition. Here's a video: Head unit? Ground issue? Capacitor? How should I troubleshoot??? Last edited by roundle; 04-18-2014 at 12:06 AM..
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04-19-2014, 02:26 PM	#2
roundle EXPAT 65 Rep 889 Posts Drives: 18 VW GTI;18 CX9;11 E91 N52 Join Date: Apr 2010 Location: USA iTrader: (0)	Turns out that this was caused by a loose optical cable connection in the rear of my “Professional” head unit. The solution was to bend the head unit’s casing a bit so that the female connector (the bit that’s built into the head unit) stopped moving around. See pics of my ingenious solution below. 1st image: up-side-down fuse box: Pulling the blue 15 at the bottom middle (well, top) was the only fuse that stopped the horrible buzzing sound. This was the fuse for the head unit. 2nd image: After pulling out the HVAC control and the cheap-o head unit, here's what you see. Note the funk sock around the cable that is attached to the antenna cable. 3rd image: WTF is this sock? Do I own a 1980s Alfa? 4th image: Here's what under the sock. WTF is this for, sat radio? 5th image: Here's the harness that plugs into the back of the head unit. Note the optical connections in holes 1 & 2 6th image: Here's a copy of the Professional radio (the cheap one) 7th image: Here's the female bit where the harness plugs in to. This is the bit that had play. When I wiggled this, I could modulate horrible buzzing sound. When I pushed the female bit in, the buzzing stopped. 8th image: My solution: Wrench on the head unit's tabs that hold the female bits of the harness to the head unit. i.e. bend them so they press/hold the stuff in place 9th image: WTF is this doing in my car? My car does not have Bluetooth. I assume that BMW added this box to enable my iPod/USB. Totally hilarious that they added this cost/weight/complexity for a y-Cable that would become outdated and unusable within 24 months. Attached Images Last edited by roundle; 04-19-2014 at 02:38 PM..
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04-19-2014, 04:26 PM	#3
taibanl Brigadier General 281 Rep 4,121 Posts Drives: BMW Join Date: Sep 2010 Location: NA iTrader: (4)	Thats the mulf-hi: yes, for ipod/usb, yes you can use it to add bluetooth for $50.
	Appreciate 0 Quote

08-17-2014, 01:41 PM	#4
Zeke3 New Member 0 Rep 16 Posts Drives: E92 328xi Join Date: Jul 2010 Location: Cleveland iTrader: (1)	This noise has been driving me crazy for almost a year. I didn't have to bend anything, and I don't have optical cables in my harness. Just reseating seemed to fix it. Thanks for the DIY!
	Appreciate 0 Quote

11-22-2014, 11:50 AM	#6
Zeke3 New Member 0 Rep 16 Posts Drives: E92 328xi Join Date: Jul 2010 Location: Cleveland iTrader: (1)	Yes, the large harness. It is blue on yours, but black on mine. Also to give an update, the noise came back as soon as the weather turned cold in Ohio. This time I went ahead and bent the tabs like you, so hope it works.
	Appreciate 0 Quote

03-23-2018, 09:24 PM	#7
gamesfrager Banned 198 Rep 709 Posts Drives: 2011 328i Join Date: Feb 2018 Location: Calgary iTrader: (0)	I was excited to find this thread, I thought it is going to solve my issue which you can hear https://drive.google.com/file/d/1PMa...w?usp=drivesdk after 45 min struggling to take the heater panel, disconnected it, removed the radio and unplugged the big black harness, I replugged it back and unlocked the car (the noise usually comes after the locking/unkocking), it was still there, but now an added loud pop, like a heart beat is also heard. I didn't bend the tabs, it was getting dark and cold. I'll do that tomorrow. From this new loud pop, I'm 90% sure it is something to do with this connector. I'll post my update tomorrow.
	Appreciate 0 Quote

03-26-2018, 09:13 PM	#8
gamesfrager Banned 198 Rep 709 Posts Drives: 2011 328i Join Date: Feb 2018 Location: Calgary iTrader: (0)	Well, sad to say nothing I can do to eliminate this noise. Replacing the radio would be super expensive. Oh well, I tried.
	Appreciate 0 Quote

03-26-2018, 09:24 PM	#9
ctuna Lieutenant General 1911 Rep 13,103 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Replacing the Radio will not necessarily be super expensive if you can do it yourself. Also http://www.e90post.com/forums/showthread.php?t=1036190 The fiber optics are displayed in the 5th picture inside the radio connector on the lower right. It impossible for a Mulf or TCU module to work without fiberoptics.
	Appreciate 0 Quote

03-26-2018, 09:28 PM	#10
gamesfrager Banned 198 Rep 709 Posts Drives: 2011 328i Join Date: Feb 2018 Location: Calgary iTrader: (0)	I guess, but still money spent. I did mention it to the dealer while the car was still under warranty. So it is on records. I'll bring it up again since the noise is more noticable now.
	Appreciate 0 Quote

12-27-2023, 08:23 PM	#11
watchout-everyone Private First Class 86 Rep 152 Posts Drives: 2011 BMW 328i Join Date: Apr 2023 Location: USA iTrader: (0) Garage List 2011 [0.00]	Thank you. This post helped me remove the noise. Condition i noticed was before fixing was - The car would make this sound from the moment it gets turned on in anyway (including initial unlocking the car) - The sound would stay on for like 10 seconds even after turning off + me exiting the car physically + and locking the car I just took it out and replugged in everything the sound is gone like 95%.
	Appreciate 0 Quote