Adding HK Subwoofer in place of storage box(long) (archive)

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I first replaced the kick panel speakers with MB Quarts RWC130. This made a major difference in the bass response, but the high range still distorted. Then, I got an HK amp. This cured the high range problem. Since I now had the extra channels for the subwoofer, I decided to try to add this to the system.

After many hours reading about adding roll hoops to HK and non HK systems, and especially Rich C�s step-by-step, I decided to gather all the parts from various buddies and BMW and do it. I knew the wiring for the sub was there as I could see the proper wires in the amp harness, but exactly where was a mystery. There as also the problem of the new top-did I really need one or could I use the existing one with the storage top hinges.

Parts I needed: Subwoofer box and speakers, various wires and spade connectors, subwoofer brackets, snorkel, HK front speaker grill(make sure it says HK), new lid bracket, new lid(if desired) various screws, bolts and fasteners, Torx 40 socket. (I have the part # for all these things although I was given some of them and bought others from buddies).

Disassembling car: I had to remove the roll hoops. This is easy. There are two access panels on the outboard roll hoop towers, and two in the storage box. Remove and back off torx screws. The hoops pull off. Next, remove the box lid(4 screws) inboard roll hoop trim, many screws from the storage box liner, and pull the liner out. The easiest way to remove the small box and lock mechanism is to pull the rear console. Remove the armrest and little black box or switch panel and undo two screws. Behind the console, pop off three trim caps and remove three screw. Lift out the rear console. Disassemble the small box and lock mechanism.

Wiring harness: I could see the wire harness through the access panel in the driver�s side seatbelt tower. With the console removed, three screws with trim caps attach the top tower. You can remove this and slide it down the seat belt. Three more screws attach the lower tower trim. Remove this. You can now pull out two plastic plugs that attach the carpeting, one where the center console was, and one under the lower tower trim. Pull the carpet forward. You can now pull on the wire harness a pull it up. Route it under the trim pieces to the center. It is a Siemens type eight pin connecter. It is not worth trying to find the matching connector, so I just cut the wire and attached red bullet connectors. Replace carpet, plugs and tower trim pieces. If you are using a new lid, now is the time to cut off the lid hinges. You don�t want to remove the entire bracket as the tenax fasteners for the boot cover are anchored into it. Attach subwoofer mounting brackets. Replace center console and armrest.

You now need to cut the wings off the storage liner. You need these parts so the inboard roll hoop trim pieces attach correctly. Use a hacksaw and cut just inside of the rectangular slots that the trim piece fits into. Screw these down with the original screws. Mount trim pieces and replace roll bars. Tighten torx screws to 18 nms.

Fit the subwoofer box in the bracket. Attach the wires first and test. If you left the hinges on, it will take some maneuvering and pushing. Screw down. Push in snorkel. Use a screwdriver to make sure the snorkel engages properly or the sub will buzz. Snap on HK grill cover. Attach the front mounting bracket for the lid. If you cut the hinges, snap on new lid. Replace all access panels and trim caps. You are done.

If you elected to use the original lid, do the following. Remove the liner and the latch from the lid. Using a dremel sander, remove enough plastic liner around the latch to accomodate the new metal bracket. Replace liner. In the screw holes that correspond to the holes in the bracket, screw in 4mm X 12 hex head machine screws. Attach lid to hinges using and offset screwdriver. Snap top down. The screws will enter the holes and lock the lid down. To open, slip a thin knife in to push the screw back and lift lid. If the lid does not align perfectly, you can bend the hinges forward or back until you get it the way you want.

The sound is well worth it. With the MB Quart kick panel speakers, the HK subwoofer vibrates the entire car for a real surround sound feel. If you can get discarded parts from buddies, all the better. Otherwise, these are the approximate prices of the components:

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