The MINI Harman Kardon option stereo system has won awards for the best stock sound system. Unfortunately several people with the HK, including me, experienced a horrible vibration from the passenger side door. Sounding almost like a blown speaker and vibrating with bass but sometimes mids as well, it quickly becomes annoying. I had the dealer attempt to repair the problem by melting the plastic rivets in the grill but it was only slightly better afterwards. It turns out fifty cents worth of felt will resolve the problem. Adding the felt instantly cured the vibration problem that I had been experiencing for months. I ended up using only half a sheet of felt for the one door. No vibration occurs even at very high volumes of bass!

I also went a step further and took the opportunity to add sound deadener, commonly known as DynaMat, to the doors. This reduces vibration of panels thereby reducing ambient road noise into the car as well as making the speaker closure (the door) more efficient at producing sound; sound quality is better and louder. Note this is NOT required to fix the HK door panel rattle problem, simply putting felt in the passenger door resolves the issue.

Later, my driver's HK woofer suddenly started grumbling like a dead speaker and then died completely. Upon inspection I found that water had been getting into the inside of the door (which is somewhat normal), and the speakers are not sealed off from this. The speaker had water corrosion on it and because of this one of the fragile speaker wires broke. I was lucky enough to get it replaced under warranty, but this terrible design oversight means it will only happen again. I bought foam speaker baffles to place the speakers in and seal them from the elements. It is another cheap and easy solution and highly recommended.

Sections:
- Removing the door panel
- Adding felt to fix the vibration
- Sound deadening
- Water protection with speaker baffles

Parts:
(1) 8.5x11" sheet of adhesive-backed felt $1.00us from a crafts store
(10) Lightweight sound dampening sheets $3.10us each from Parts Express
(1 pair) 6.5" foam speaker baffles $7.99 such as these from Crutchfield or from Parts Express

Tools:
Torx30, small flat-head screwdriver, large flat-head driver wrapped in tape, scissors

Time:
30 mins

Removing the door panel

Use a small screwdriver to carefully pry the reflector out, using the indentation in the top rear (Careful, these break easily). This will expose a torx screw.

Also pry off the handle/tweeter surround, from the center of the front bottom side.
Remove the four torx30 screws, noting their original locations as they are different sizes. NOTE: 2005+ models have the lower rear screw covered by the rubber armrest. Slide something plastic underneath it at the front to release the tab to remove the rubber and expose the screw. See Ian's photos demonstrating this.

Next take a large flat-head screwdriver, and wrap a good length of it with duct tape or similar. This is just to prevent it from scraping the paint. Use the screwdriver to pry the door from several clips around the front, bottom, and rear edges. Easiest is to start from the bottom rear corner.
The door panel will pull forward hinged from the top when everything is off. Pull to about a 45-degree angle, then up and out to release it from the top four clips.

When replacing the door panel, first put the door lock through its hole in the door panel. Then push into the top clips by the window seal. Then carefully align the lower clips into the metal door. Hit the door panel around the edges using your hand to clip in place. Replace all the torx screws, tweeter surround, and reflector.

Fixing the vibration with felt

The main issue with the HK is that the strong bass vibrates the door panel, and its edges hit the metal door and cause the annoying vibration sound. Simply adding felt to the areas where these edges touch the door nearest the speaker fixes this issue. Cut pieces of felt from the sheet and apply them where the panel would meet the door. Remember to punch holes for protruding items and holes for the clips:

The plastic behind the grill may also be striking the plastic speaker mount, so it is a good idea to add felt there too. Cut and apply felt to the circumference of the grill back:

Sound Deadening

There are two basic levels of sound deadener/DynaMat, both come in sheets and rolls with a peel-off adhesive backing. The basic type is made of asphault, then there is a lighter, higher-performing version made of other materials (For example DynaMat Extreme). I chose to get the higher performing vinyl type but in cheap generic form from PartsExpress, which is much cheaper yet perferoms well and saves weight. When you open the panel you will notice MINI has already placed a rectangular piece in the center of the door metal. I cut and added sheets to the rest of the door inside, as well as to the door metal near the speaker. I also applied some to the door panel as well, as pictured below, to hopefully further reduce its vibration. Be sure to apply pressure all around the sheet when applying.

Water protection with speaker baffles

The back of the speakers are exposed to the inside of the door. Water can get in through the window seal, and large amounts may fall onto the speaker. Here is what happened to mine, corroding the speaker wire until it broke:

This can be resolved with a pair of foam speaker baffles. Order 6.5" diameter, 3.25" depth. (Pictured are mine from parts express which are 4.5" deep and too deep). Slice a small hole in the bottom to pass the speaker connector through. Unscrew the four phillips screws and slowly pull the speaker off the door from the top. Disconnect the speaker wire connector.

I trimmed the corners of the baffle so they don't stick out from the door panel. Place the baffle in the door, reconnect the speaker and place it in the baffle. Screw the speaker back into the door.