# HK audio system causes front door rattles in E46



## Terry Kennedy (Sep 21, 2002)

Ok, I've got a 2003 325xiT Sport Wagon (but this should apply to any other 3er with HK as well). I'm finally getting around to chasing down the various rattles coming out of the audio system. To start with, I don't listen to music at overly loud volumes, and I don't crank up the bass. So there shouldn't be any factory rattles, right?

I've got the BMW audio test CD and the Denon Audio Technical CD, and I just spent a couple hours in the car trying to reproduce some of the rattles. I managed to find some I didn't know I had (I never noticed that the fuel filler door is mounted on the other side of one of the interior subs, and I had some spare fuses rattling in their box in the glove compartment) but I couldn't get these discs to generate the obnoxious "blown speaker" sound I get from some CDs.

So I put on a bunch of the problem CDs (thanks to the Phatbox, I don't have to actually swap CDs) and held my ear to the front passenger door (which is where the majority of the current rattles seem to be coming from). It seems as though the rattles are not from the speakers themselves, but from other components inside the door, which happen to resonate at specific frequencies (but only on complex waveforms like music, not from the test CD sine waves).

Other than disassembling the door, tightening everything down, and covering everything I can with deadening foam, is there anything else I should do instead/in addition to that? I don't want to take it to the dealer (my experience is that I either get a "can't reproduce" or "turn down the volume" type answer, or I get the car trashed (Bozo the Eagle Dealer actually took my new Talon apart and put it back together with drywall screws!) and the problem doesn't get fixed anyway.

Oddly, when I first picked up the car the most annoying rattle/buzz was from the driver's side near the tweeter. Now that one seems to have faded and the bad one is from inside the passenger's door near the handle/midrange speaker.


----------



## ObD (Dec 29, 2001)

FWIW, you should go with a custom audio system if you are any type of audiophile. The kind of frequency analysis you are asking for has to be done in the design phase. I doubt any manufacturer would go to these lengths to fix an audio system that for the most part the average Joe is happy with. The HK is a $700 upgrade and it will never sound like a $3000 system. :soapbox:


----------



## Nick325xiT 5spd (Dec 24, 2001)

My understanding is that BMW has a fix for it. I've found that keeping my manual book in the passenger door, and a big CD wallet in the driver's door largely alleviates the rattle/buzz.

Next time my car goes in for service, this will DEFINITELY be on the list.


----------



## Nick325xiT 5spd (Dec 24, 2001)

ObD said:


> FWIW, you should go with a custom audio system if you are any type of audiophile. The kind of frequency analysis you are asking for has to be done in the design phase. I doubt any manufacturer would go to these lengths to fix an audio system that for the most part the average Joe is happy with. The HK is a $700 upgrade and it will never sound like a $3000 system. :soapbox:


 Did you even read his post? He was :nono::nono::nono::nono::nono:ing about how the stereo causes his CAR to rattle, not about the poor quality speakers sounding like shit. (In fact, the stereo in the wagon sounds fairly decent. My only guess is that the acoustics are better. The sedans I've heard have been awful.)


----------



## Terry Kennedy (Sep 21, 2002)

Nick325xiT 5spd said:


> Next time my car goes in for service, this will DEFINITELY be on the list.


Please report back if they managed to fix it, and more importantly, what exactly they did. Thanks!


----------



## ObD (Dec 29, 2001)

Nick325xiT 5spd said:


> Did you even read his post? He was :nono::nono::nono::nono::nono:ing about how the stereo causes his CAR to rattle, not about the poor quality speakers sounding like shit. (In fact, the stereo in the wagon sounds fairly decent. My only guess is that the acoustics are better. The sedans I've heard have been awful.)


The custom install would eliminate the rattling due to the use of more and better sound absorption materials, and better care not to incite said frequencies. Unless you redesign every piece and material in the car so it isn't excited by the audio system, there is nothing you can do. To illustrate my point:

http://www.wcsscience.com/tacoma/bridge.html


----------



## Terry Kennedy (Sep 21, 2002)

ObD said:


> The custom install would eliminate the rattling due to the use of more and better sound absorption materials, and better care not to incite said frequencies. Unless you redesign every piece and material in the car so it isn't excited by the audio system, there is nothing you can do.


To reiterate - I'm not looking to run this system at loud volumes or with heavy bass. What I have is apparently something that isn't tightened down properly. Remember, I had this on the left door and it went away.

I do have a high-end home system with active room correction and I know what you're talking about, but this is something that shouldn't be happening at the levels I'm listening at - as I said, from a distance it sounds like a blown speaker, not just a minor rattle. Sure, with enough volume we can get most of the car to rattle, but this isn't that.


----------



## Parump (Dec 25, 2001)

Terry,

Glad you returned!


----------



## Terry Kennedy (Sep 21, 2002)

Parump said:


> Terry,
> 
> Glad you returned!


Thanks!


----------



## CPS (Mar 24, 2003)

I have the same problem. An intermittent rattle from the passenger door (or maybe the glovebox or vent). I have a 330Ci with H/K. Its starting to drive me crazy. If BMW has a fix, is there a TSB or other way to identify it for the dealer?


----------



## Jsteb (Jun 5, 2003)

*Same here...*

my two week old '04 330Ci has the passenger door buzz/rattle too (but sometimes it sounds like it is coming in from the center console near the vents)... it was going crazy this morning. I will be taking it in soon and let you know what they come back with from service.

Also, I know that there are 12 speakers in the HK system... but I can only visually count 10... where are the other two? (I have included the subs in the trunk with my count)


----------



## Technic (Jun 24, 2002)

Terry Kennedy said:


> Ok, I've got a 2003 325xiT Sport Wagon (but this should apply to any other 3er with HK as well). I'm finally getting around to chasing down the various rattles coming out of the audio system. To start with, I don't listen to music at overly loud volumes, and I don't crank up the bass. So there shouldn't be any factory rattles, right?
> 
> I've got the BMW audio test CD and the Denon Audio Technical CD, and I just spent a couple hours in the car trying to reproduce some of the rattles. I managed to find some I didn't know I had (I never noticed that the fuel filler door is mounted on the other side of one of the interior subs, and I had some spare fuses rattling in their box in the glove compartment) but I couldn't get these discs to generate the obnoxious "blown speaker" sound I get from some CDs.
> 
> ...


It seems that you are going to the same dealership that I am... 

You are right in your assessment of the culprit of all these little rattles and vibrations: the door panel and/or internal mechanism. I initially thought that they came from the speaker, but by just pressing against the door panel (any front door that rattle) while the rattle starts I have been able to supress most of it.

There is a solution that I read in the roadfly.com site some time ago that involves some foam pads integrated with the door pins (the plastic pins that holds the panel against the door metal frame). The idea is to make the panel tight and isolated enough that any resonance caused by the music frequencies is absorbed by the foam. I do not remember if this person came up with the idea or is something that his dealership came up with. But it seems that it worked for this person, and it makes a lot of sense...


----------



## Terry Kennedy (Sep 21, 2002)

Technic said:


> You are right in your assessment of the culprit of all these little rattles and vibrations: the door panel and/or internal mechanism. I initially thought that they came from the speaker, but by just pressing against the door panel (any front door that rattle) while the rattle starts I have been able to supress most of it.


I think I may have found it when I had the doors apart to install the power folding mirrors. The midrange speaker has a rather lame connector retaining mechanism - it uses the usual 2-pin AMP connector, but the mated connectors snap into a clip that is part of the back of the speaker. I just dabbed a blob of silicone on the whole thing to keep it from rattling. The same type of retaining clip is used inside the door foam liner (up by the HK tweeter) to hold the tweeter's connector and the window pinch tapeswitch connector. Since I had the foam open to install the power folding mirrors, I gave those a shot of silicone goop as well. I checked the tightness of the sub mounting screws (3 Philips) and the midrange retaining ring as well, and tightened those up a bit. The screws on both the driver and passenger side were about 1/4 to 1/2 turn loose, the driver's side midrange retaining ring was fine, and the passenger side ring was about 1 turn loose.

I'll have to give this an extended road test to make sure I got all the rattles, but I have high hopes.


----------

