February 4, 1999
By: Robert Leidy

Over six months have passed since this stereo upgrade initially began, and there are several things that have happened so I felt the need for a "six month update". I will go into detail one issue at a time below but basically I'm happier with the stereo, but even more upset with Earmark Car Audio, the stereo shop that initially installed everything. At this point there is not much of the upgrade that was initially installed that hasn't been uninstalled and reinstalled by someone else.

Amplifier Heat

This is no longer a concern for me, the a/d/s/ amp is running relatively cool with the help of the four additional fans. When I compared the temperature in my trunk to the temperature in other Z3 trunks during the homecoming convoy, I discovered that I am well within the norm. Most (stock stereo) trunks were cooler than mine but not by much, and any Z3 (with the exception of Alan's) that had an upgraded amplifier were actually running hotter. I am happy to report that the a/d/s/ amplifier has never shut itself off even with extended high-volume stereo listening. The radio shack digital thermometer was very handy, during the homecoming convoy I was able to toss it into a different Z3 trunk every time we stopped for fuel. By the end of the trip I had a very accurate representation of what was acceptable and I was within that range.

Boston Pro 6.4 Speakers

I was disturbed to discover that the passenger side tweeter stopped working one day. It took nearly two months but a replacement was delivered at no cost. The speakers still sound great, but a recommendation is worthless at this point since the 6.4 model has been discontinued.

Alpine Bass Shakers

While my M roadster was on the lift at BMW one day I asked the Tech "what are those sheet metal screws". He smiled at me and said "those are holding down your bass shakers". I could feel my blood pressure rise as I looked at these inch long sheet metal screws ripped through the bottom of my M roadster. One of the screws had been bent (probably from a speed bump) and the installer hadn't even put any kind of sealant around them to stop water/rust. The BMW Tech cut the screws off so they didn't stick down quite so far and added some sealant but the damage had already been done. About a month later that bent screw finally gave up and the drivers side bass shaker shook itself loose and was now a bass rattler.

One weekend I ended up taking out both of the M roadster's seats and then removed the bass shakers. I reinstalled the bass shakers using nuts and bolts and a generous amount of sealant. Once everything was reinstalled the bass shakers were working as good as they had ever worked, however my opinion of them has gone way down over the last six months. Their shaking affect is quite impressive when the car isn't moving. However once the car is moving at more that 30mph the slight vibrations from normal driving seem to cancel out the bass shaker affect. Maybe they work better in other cars, but the sports car (stiff) suspension in my Z3 appears to make the bass shakers a poor decision.

BMW subwoofer

Finally some good news, for several months a/d/s/ has been using my BMW HK subwoofer to develop a upgrade kit. I haven't received the finished product yet but they are telling me they have made some improvements to the stock enclosure and are now using two new drivers. I can't wait to hear it in my car.

Rear Speakers

The desire for rear speaker fill has hit me, I'm going to hold off until I get the a/d/s/ subwoofer installed but I suspect I will be adding some rear speakers (myself) sometime this summer. I will probably work them into the same channel as the bass shakers or a/d/s/ sub via some external crossovers.

BMW CD Changer

The rumors about the M mobility kit and its interference with the side mounted CD changer were correct. To get them to fit in that location the gray flannel cover must be removed. It might be my imagination but the CD Changer also seems to be skipping more frequently. I'm starting to second guess my decision to keep the BMW equipment rather than get an indash CD player.

a/d/s/ Subwoofer