I recently bought a 2006 BMW M3 with a competition package and a few other options like HK Premium sound. The stereo was decent but it still sounded hollow or like it was playing through a tin roof. You could turn down the treble but then the music sounded flat. I debating installing a whole new system but then I remembered BavSound who makes model specific upgrade kits for BMWs.
Even the base stereo upgrade kit for the E46 is different than the HK system. Apparently the main speakers are 2ohms on the HK but 4ohms on the base system. So order the one specific to your car. I have to admit I was a bit skeptical buying a whole package of speakers for roughly $500. If you look at the top of the line aftermarket speaker they can more than $500 for just one set and there’s nothing custom. Not only are the BavSound speakers matched to the original speakers but the wiring is plug and play too. Meaning you just just unplug the old speaker, plug in the new, replace the three screws and put the cover on.
I have to say that I’m blown away by the improvement in sound quality. My friend Steve ordered a kit for his E90 the week after he helped me install mine. Once you hear a set installed, the BavSound kit makes so much sense that I can’t imagine going the hassle of installing a complete aftermarket system. Just get the upgraded factory option, call BavSound, change speakers, and enjoy.
The installation took me about 90 minutes to get through all the speakers. Once the front door card is off, the process is pretty straightforward. There are plenty of YouTube videos that show you how to take the car apart, let me know your google is broken. The pictures that follow are the old HK speakers followed by the new BavSound kit. If you’re done reading, at least scroll down and check out the custom brackets and wiring on the tweeter and midrange. The kit really was designed just for the E46 BMW. Pretty cool.
Can you see a speaker’s sound? If you can, this speaker makes much better sound than the factory speaker I’m replacing. The woofer itself looks like a carbon weave of some sort. The rubber ring that the woofer floats on looks well made thicker than the cheap foam on the original factory speaker shown above.
It’s pretty cool that all the regular speakers fit perfectly but even more impressive are the custom fit speakers like the front door of the E46 M3. There’s a little mid range and tweeter in a plastic housing that bolts to the door. BavSound sells this whole unit(part of the kit) that fits directly into the old speakers spot.
The magnet on the back looks way larger than the factory speakers and even though the speaker cage is stamped its thick and a quality piece. Keep in mind the speakers needs to fit in a pretty tight spot on the door so design wasn’t unlimited. It also needs to work well with the factory ampiflier. 
Here is a good example of the plug and play wiring. Everything is a direct fit with the proper plugs.
I also took a second to upgrade the subwoofer. BavSound doesn’t make subs for the E46(they do make awesome underseat subs for some of the newer models) so I bought a random set of 6×9 subs and put them in too. These are the original factory speakers which as you can see aren’t very robust. Im not sure if you can see a speakers sound, but this doesn’t look like it makes a lot of sound. 
I over did it on the subs because the rear deck lid rattles like crazy on long slow base notes. There is a subwoofer button on the dash to turn it off, but the car produces so much base from the BavSound speakers that maybe I should done something different or more tunable with the subs.
The whole setup sounds amazing now. Substantially better than stock and easily worth the $500 or investment in new speakers. I’m seriously blown away by the improvement in sound. Nice work BavSound. You guys can order your speakers here. And just in case you were wondering, I paid for my speakers and was not influenced in any way other than by the quality of my purchase.
