E46 Fanatics Forum banner

How to fix your HK sub/rear deck rattle! *30 Photos*

100K views 67 replies 52 participants last post by  sloveniaboy 
#1 · (Edited)
I have read a couple of DIY's and explanations on how to fix the common problem of the Harman/Kardon subwoofer system rattling the rear deck/parcel shelf. They all offer a different method of solving the problem, so I just wanted to post some photos of the process I used to fix the rattle and to make it clear exactly what must be done to perform this fix.

Here is a photo of the Harman/Kardon subwoofer. It is located underneath the rear deck/parcel shelf in the trunk.



There are 4 black screws and 2 white clips which hold the subwoofer in place. Note that there are no screws holding the rear of the subwoofer.

Left screw:



Right screw:



Center screws and white clips:



Step 1: Remove the 4 black screws using an 8 MM wrench.





Step 2: Remove the rear tabs holding the rear of the subwoofer in place. This is easiest if you crawl into the trunk and lay down on your back facing the bottom of the subwoofer. Push out (towards the rear of the car) and pull down on the subwoofer. The photos below illustrate how the sub's rear tabs will come out of the holes in the upper mounting structure.



Step 3: At this point, the subwoofer will be held in place only by the white clips. You DO NOT remove these clips from the subwoofer itself. Instead, while still lying on your back in the trunk, pull down on the front part of the subwoofer. Use some muscle, and the clips will *pop* out of their retaining holes along with the subwoofer assembly.



Step 4: The only thing keeping you from taking the subwoofer out of the trunk at this point is the power connector to the rear of the subwoofer. Simply pull the connector off to disconnect it from the subwoofer.



Here is the HK subwoofer assembly removed from the vehicle:





Here is a photo of the white clips that were discussed earlier. Previous DIY's have instructed the user to either remove or even break these clips. As you can see, they remain in the HK sub assembly and are removed with the unit as a whole. You do NOT have to break these white clips in order to take the subwoofer out!






Here is a photo of where the HK subwoofer mounts in the trunk. The 2 large holes you see in the steel structure simply allow sound to travel into the cabin rather than reflect off the metal if it were a solid continuous structure. These holes are where we will be stuffing our sound insulation to stop the deck rattle. The second picture points out the bottom of the rear parcel shelf as seen through the trunk.





My car was purchased used, and I believe that the previous owner brought this car into the dealer to try and fix the rear deck rattle at an earlier point in time. They used a small 3/4" thick/2" wide/3' long piece of foam and filled the rest of the space with yellow expanding foam (as pointed with the red arrows in the photo below). This solution obviously did not work! Also note the center hole in the steel structure (which is circled in red). This is the hole in which you can thread a carrier bolt to push against the bottom of the rear parcel shelf as per the "bolt" DIY from this link (however we will not be using a bolt in my particular DIY):

http://forums.bimmerforums.com/forum/showthread.php?t=132399



Before we begin stuffing the inner rear deck area with insulation, we must first decide what materials to utilize. A previous DIY suggested using bubble wrap, which is a cheap, viable solution. However, I chose to go with a polyester batting material which is perfect for this application. The batting will eliminate the rear deck rattle, as well as aid in giving the subwoofers more of a "thud" sound by providing extra insulation and sound deadening.



After some trial and error, I decided to cut the material into 2 large and 4 small sections. However, it turns out that I only used 1 large section of material and 2 small sections of material.





Step 5: Take the large section of batting material and stuff it in the center of the rear parcel shelf area, bridging the gap between the two large holes.

 
See less See more
20
#36 ·
The dealer's fix never did work for me. I finally broke down and took a shot at fixing this myself. Now I hate that I waited!

Since the goal is to stop the deck itself from resonating I used the bolt method. It never made sense to add more insulation. All that does is deaden the sound. The bolt method worked like a charm. I found some of the dealer’s old insulation, now unglued, under the deck. I took a piece of that to cushion the bolt against the deck. Worst case the insulation will break down and I can replace it or adjust the bolt. I can’t see how I’ll ever worry about it popping through. Total cost, 70 cents for one bolt and two nuts.

I do wonder about one thing. When I removed the sub woofer it looked like someone had drilled holes in either side of the plastic housing. I see them in the pictures on this post but this car also appeared to have the dealer fix. Can anyone say was this part of the dealer fix or how the subwoofer came from the factory?
 
#37 ·
For those that do not have the oem SUBS (fr. the HK system), use old t-shirts. There are DYI instructions on how to do this on this forum.

The key is to get the T-shirts/whatever you feel like using, allllll the way in so it pushes the entire deck up a little. Use a rod or something stiff and thin. Push the shirts so they end up right where the rear windshield and the trunk meets (at the bottom)...

To give you a larger gap, unbolt the 3 bolts (w/ covers) on the deck...

I did this last night, and it worked like a charm. I'm so happy. :)

F**king rattles!
 
#39 ·
i will do this in near future. I put in sponges in small holes without removing hk sub. It was pain in the ass to get sponges in through that small holes. Maybe next weekend or one after I'll remove sub and put in lots of sponges to keep that deck without rattle.

What do you think about sponges? is it ok material?
 
#41 ·
#42 ·
at the risk of sounding ghetto I just stuffed 3 tennis balls in the area you stuffed your things. It doesn't rattle anymore. The tennis balls are flexible enough to get in there, but apply enough pressure to prevent the two planes of the rear deck to vibrate and rattle. Quick, painless, and easy and took all but 5 minutes :thumbsup:
 
#47 ·
Props to the original poster. The detailed images were very detailed and informative. The hardest part was unlatching the electrical connector to the HK subs lol. A tip for someone doing this project, make sure you push the sound deadening material deep into the edges to make sure the rear deck is not loose. The sound difference is amazing and feels like I just upgraded my whole sound system. Nothing but clean music.

Before the fix, my girl's 05 Altima's sound system was better than mine. Now, there is no comparison, the HK sound system sounds like it was meant to.
 
#48 · (Edited)
Hi - new to the Board, so bear with me, and thanks to the original poster for his detailed pix.

Bought my 2005 325Ci on the Easter weekend a month ago, and noticed the rattle right away. Spent awhile surfing this board and others looking for a fix (used to have a Z3 Coupe and an E36, so used to fixing small things by surfing message boards). Bought my $2 bolt and hex nuts last week, and this morning, went out to do the "bolt" fix.

Imagine my surprise when I yanked off the sub housing to find an 8mm bolt in the spot where the "bolt fix" is supposed to go:



It's holding up a white plastic brace, which I hope you can see:



Is it a factory fix? Or am I on happy pills? The last owner was definitely NOT an enthusiast, so he didn't do it. The car was built in Feb 2005. On no other thread did I hear that there was this kind of fix, so I suspect it's custom. Didn't work anyway - ended up stuffing in 3 old wash mitts :).
Thankx.
 
#51 ·
Chuck- I have a 4/05 model and it has the same thing. That screw anchors down a leg of that white piece. I spent $3 on a tube of tennis balls and stuffed them in the middle. It was pretty obvious the that BMW was aware of this and changed production, as I had plenty of insulation and other stuff back there compared to the OP.

Tennis balls, doesn't get much easier than that :thumbup:
 
#57 ·
Does anyone know what the model number of the JL stealth subs to replace my HK factory subs ? Crutchfield said because of clearance concerns, nothing would fit . ( I appologize if I it appears that I am hijacking your thread) please forgive me . I am a newbie trying to get some bass. LOL!
 
#59 ·
Just did the repair. Turns out BMW installed the plastic bracket in the photos above but didn't bolt it down, man was it rattling! I also stuffed three tennis balls inside for extra support, worked perfect. Took maybe 20 minutes to complete.

Thanks for this DIY...
 
#60 · (Edited)
Sorry to bump and old thread, but I just took off my sub and that white brace is there and its bolted very tightly in. The deck doesn't seem to be loose at all, it seems really solid.

I feel like the rattle is coming from the mid sized drivers on the side of the subs. Anyone know how to remove these?

EDIT: I did find out how to remove the "mid subs" but those weren't the problem. The problem was the deck rattling very far near the "mid subs". I guess it was so far to the side I didn't notice the play in the deck. I shoved a tennis ball on each side as far as I could to the side and I have no rattle SO FAR.

Thanks once again e46fanatics, you're awesome!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top