HK Sub Dissected

You can get to the HK sub by snapping off the lid on top of the rear compartment. The lid is attached in four spots. The forward snaps will give way first. Just make sure to keep the lid flat and pull straight up.

The subwoofer is held in place by four screws. Be careful removing the screws because if you drop one it might be difficult to find. Once the screws are removed, you can unhook the wiring harness that attaches the HK sub (it’s tough to undo the first time).

Once the enclosure is removed, you can see how the process was designed to work. One speaker is facing forward and is ported out the front grill into the cabin. The rear speaker is not ported at all; it is wired in reverse phase and is solely designed to assist the front speaker (not to be heard on its own).

The HK sub has two speakers within the plastic box. The rear speaker (pictured on the right) is exposed. The wire plug (coming out of the left side) contains four wires, two for each speaker. (Click on any of the pictures for a larger view).

Looking inside the port hole you can see the second speaker. It is identical to the one on the back. Inside the cavity there is some stuffing. Playing around with the sound characteristic, I found that the sub sounds better at low volume with the stuffing removed, but it sounds much better at high volume with the stuffing. I say high volume, but truth is these are speakers that just can’t handle very much power. The HK sub is a really good sounding speaker up to a point, then everything starts to buzz and rattle.

Some stickers on the speakers claimed 2 ohms, but using an ohm meter, I tested each individual speaker at 3.4 ohms. It would be very interesting to try and find some really good aftermarket speakers that would fit in the same enclosure. I measured the speaker mounting points – it was 4 1/4 inches from the outside of one hole to another and 3 3/4 inches from the inside to inside (click on the picture to the right for a larger view). If anyone finds a possible replacement speaker that will fit, please tell me about it.

You can see there really isn’t much to this design. It’s a plastic molded speaker housing that has just enough room to contain the two speakers. Because of the compact design, there is not a lot of room for air to move. I think the tight design really leads to high air pressure, and the paper/cloth drivers perform up to a point but then the increased air pressure just restricts their movement and they start to distort. But all in all you have to really be impressed with the capabilities of such a small design. I think they could be improved upon, but not bad for stock speakers.

Babes in Toyland

I’ve always had models of my current car. I started with a Renault R5, moved on to 2 VW Sciroccos, followed with a Miata and now that I have a Z3, I needed a suitable scale model to display with the rest. I had found a couple of models which were red 2.8’s or black 1.9’s, but I wanted a black 2.8. The Baba had suggested that I contact

I called the number on the page and started talking to Michael J. Izor – a self-confessed car model addict. Michael’s tastes in mini-cars is very narrow, he only collects BMW’s. However, he’s managed to collect over 4500 of them!

I think my request for a black 2.8 Z3 seemed sort of mundane to Michael. He’s used to harder challenges. He checked his inventory and told me it was mine for $28.50 plus tax plus shipping. Plus shipping! Hey! He’s only out in Natick! I could just drive out there and get it! Michael seemed amenable to a visit, so we set up a time.

It was a great day for a drive! The sky was blue, the sun was hot and the road was long and twisty! Michael lives in Natick, Massachusetts about a half hour from my home. Natick is a lovely town, filled with old trees and old victorians. Michael says he “lives in a beautiful, big old Victorian home, in a state of elegant decay (yes, both of us)”. We found the house without too much help (thank god for cell phones). Michael greeted us at the door as he picked up his mail – more toys, no doubt.

Michael took us on a guided tour through his wonderland of mini-cars, models and toys. Before seeing it, I could not imagine that there were 4500 different BMW models in existence. Michael has turned his home into a museum, devoted to miniature BMW’s.

There are several display cases in his office where he also has his computer. The cars are not arranged in any particular historical sequence, but they do tend to be grouped together by model or by size.

Leaving his office, there is a long hall lined with the smallest cars in his collection, the 1/87 scale models. Each one of those cases contains about a hundred cars! I immediately found the sections devoted to the Z1’s and Z3’s.

Michael’s collection runs from classic BMW’s to BMWs of the future, like the Alternative Fuel car (which never saw production as a real car, but, quite unusually, got to be a production model in 1/43rd scale.)

The crown jewel in Michael’s collection cases is this old display case from a dentist office. It houses some of his older collectibles, including a small silver 2002, his first miniature which he purchased, along with a full-scale 2002 in 1970. Michael paid $1 for the 2002 (the small one). It was only the first of a large number of dollars which have gone towards his “hobby”. Michael worked for many years as the CFO of a local television station, but has now decided that buying and selling model cars (mostly buying, he admits) is a much more fun way to make a living. We agree!

Michael’s collection rambles on from room to room. It includes memorabilia, much of it from his years as BMWCCA treasurer and president. He showed us this neat little gizmo which was designed by BMW engineers. It’s a miniature set of pistons which are driven by a solar panel – a remembrance of a particular conference held by BMW.

Although reception to the Z3-coupe has been somewhat lukewarm on the Z3 board, Michael had no hesitation adding one to his collection.

We had a great time at Michael’s. After the tour, he gave me my model 2.8 and we took the long way home, knowing we were driving not one, but two BMW Z3 2.8’s! If you’re in the Massachusetts area and are looking for a little bit of BMW to put on your desk or shelf you should be sure to give him a call. If you’re lucky enough to get an audience at casa-Izor, take him up on the offer of a tour!

However, it was time to go home and play with my new toy and add R281MNX(2) to the collection:

Magnetic Stone Guards

Pros: Looks great (911-ish), Protects from paint chips, Easy to take on and off
Cons: none?
Cost: $39.95 pair (from Z3 Solution)

The rear wheel wells on the 2.3 Z3, 2.8 Z3 and M roadster stick out quite a bit. A few owners started picking up rock chips in this exposed area. Porsche ran into similar problems with its 911 and solved it by adding some sporty looking protective pads.

The say imitation is the sincerest form of flattery, Keith got the idea to create some stone guards for the Z3 based on the 911 design. Using the same thin magnetic material that people use for those stick on door advertisements. Keith’s original design (pictured on the right) was cut to match the contours of the fender flair.

Later Keith redesigned the shape of the stone guards, the protected area is slightly larger but basically the new design is just cosmetically different from the original design. Using the stone guards is pretty simple, it took me a couple minutes to get them installed “just right” the first couple times but now after some practice I can slap them on pretty quickly (for me the secret was to start at the bottom first). As far as care and maintenance goes, I remove the stone guards every time I clean the car and hand wash them with soap and water. I always make sure to dry them off and I never put them back on until everything is dry (don’t want water trapped under them). When I wax the car I give the front and back of the stone guards a layer of wax at the same time.

Keith also has some new chrome versions of his magnetic stone guards, the chrome version really makes a statement. Not sure if the chrome ones will visually work on every car, but on some colors they should look pretty cool. Keith sells these and a few other “Z3 Solutions” via his web site. He also has a gallery of pictures of Z3s with his stone guards on if you want to see some more examples.