2000-2006 BMW 3 Series coupe
How to upgrade the stereo system in your 3 Series coupe
In brief: This Crutchfield Research Garage article gives you an overview of your BMW's stock stereo system and your aftermarket upgrade options. We'll tell you all about:
- The factory stereo system
- Removing the factory radio
- Removing the factory speakers
- Adding more bass
- Other options for your 3 Series
Then, use our vehicle selector to find the gear that will fit your BMW 3 Series coupe.
Overview of the BMW 3 Series
The BMW 3 Series has grown and changed a lot over the years, but it's never lost that certain something that makes it, for many, the finest sports luxury car in the world. That's why almost any car magazine's annual "top ten" or "best-of" list is pretty much guaranteed to include a 3 Series.
It's kind of become a cliché, but hey, the car really is that good. A lot of manufacturers have tried to imitate and improve upon the 3's all-around excellence, but few have succeeded with any consistency.
The fourth generation 3, known internally and to BMW experts as the E46, offers a wonderful combination of comfort, power, and driving feel. In coupe form, it's a sleek, sporty-looking machine that's still quite practical for everyday use. The styling, which was a bit controversial back in the day, has aged remarkably well, while the interior remains a comfortable, well-designed place to spend time.
The standard radio is the easiest one to replace (Crutchfield Research Photo)
The factory stereo system
As wonderful as the driving experience might be in a 3 Series coupe, the audio experience was rather less impressive. We've seen the stock systems described as "muffled," and that's never a good thing.
Even if that's just a few people complaining, the fact remains that the receiver and speakers are aging rapidly, so if you're serious about sound, you'll want to replace them. Upgrading the factory audio isn't necessarily easy, but because iDrive had yet to trickle down to the 3 Series, it's easier than it could be.
The factory system consisted of a base BMW-branded AM/FM/CD receiver (or cassette, in early models) and ten speakers. The optional 12-speaker Harman Kardon system, used the same radio, but added better speakers and a subwoofer. A trunk-mounted CD changer was another audio option.
A trunk-mounted CD (later DVD)-based nav system was also available on the 3 Series, and the route information was displayed on a variety of receivers with ever-larger screens over the years.
The optional nav radio is best left alone, unfortunately (Crutchfield Research Photo)
Removing the factory radio
You’ll face different installation scenarios, depending on which factory system you have. The standard radio is no big deal. The Harman Kardon system adds a little twist. The navigation system is a deal-breaker. We’ll discuss all three situations below, but the best solution is a complete system overhaul — replacing the receiver, factory amp(s) and speakers. If speaker-only replacement is your best option, look for aftermarket speakers with an impedance equal to or greater than that of the factory speakers.
If you have questions, give us a call and let our expert advisors help you find the gear you need. After your purchase, you'll have access to our Tech Support team for the lifetime of your gear.
Detailed stereo and speaker removal instructions
Standard BMW stereo system
Replacing the standard "BMW Business" stereo with a single-DIN (2" tall) receiver is a challenge, but it's thoroughly within the capabilities of most DIY-oriented car owners. There's a bit of trimming and adjusting to be done, but other than that, this is a straightforward project.
Installing a receiver with a fold-down face might seem like a good idea, but the screen will block the center dash vents, so we don't recommend it. The good news is that replacing the stereo is much easier than it is in other systems, so let’s get to it...
Using a panel tool, pry off the plastic trim above the glove box. Then, pry off the trim strip above the radio. You'll want to work carefully here, because you don't want to damage these plastic panels. With the panels out of the way, you'll need to remove the two Phillips screws securing the factory radio. Pull it out, disconnect it, and remove it.
This dash kit is included at a discount when you buy your receiver at Crutchfield
Remove the DIN sleeve and trim ring from your new stereo, then trim off the tabs located on the top of the stereo trim plate. You'll want to test fit the stereo by sliding the DIN sleeve, then the stereo, into the dash. Check the mounting kit on the face of the receiver to make sure it's flush. If the receiver sits too deep into the dash, the installation kit includes a spacer ring that can be placed behind the sleeve to space the stereo outward.
From there, connect the receiver wiring adapter (also deeply discounted) to the stereo's wires following the included instructions. Slide the DIN sleeve (using the spacer ring if needed) into the dash. Secure the sleeve by bending the securing tabs.
Hold the stereo near the dash, connect the receiver wiring adapter to the factory harness and plug in the antenna lead, using the antenna adapter. Slide the stereo all the way into the sleeve, then install the mounting kit trim plate and secure it to the dash using the screws you previously removed.
As noted above, replacing the nav receiver is anything but straightforward, so we recommend turning that project over to a car audio professional.
Harman Kardon stereo system
When you replace the radio in a car with the Harman Kardon system, you’ll also need a special adapter called a line output converter. That's because the factory amplifier requires a low-level signal from the new radio.
As we've already hinted, when you purchase your new stereo from Crutchfield, we’ll make sure you get all of the installation gear you need (mounting kit, wiring harness, antenna adapter, AND this line output converter), plus we'll also give you a deep discount on them. Just make sure you use our vehicle selector so we know what you need.
Stereo with factory navigation system
Replacing the navigation system’s radio is not something to undertake lightly. It requires extensive modification. You’ll have to fabricate a custom mounting kit – there aren’t any ready-made aftermarket kits available. You’ll also have to extend the wires from the wiring harness all the way to the trunk, through the length of the car, where the car’s tuner/amp module is located.
This is not a job for the average do-it-yourselfer and we don't recommend trying it. That said, if you HAVE tried it already, feel free to share your trials, tribulations, and successes in the comments below. We'd love to hear from you, and we're sure your fellow owners would too.
Tools needed: Phillips screwdriver, panel tool, small flat blade screwdriver, utility knife
Read our Car Stereo Buying Guide for shopping tips and advice.
Steering wheel audio controls
In most cases, it's reasonably easy to retain your BMW's steering wheel audio controls when you install a new stereo. When you enter your vehicle information, our database will choose the adapter you need to make your factory steering wheel controls work with a compatible aftermarket receiver.
The coupe's big doors can hold some very nice aftermerket speakers (Crutchfield Research Photo)
Removing the factory speakers
The 3 Series sedan has speakers in the front doors, rear doors, and rear deck. The Harman Kardon system adds a couple of small woofers on the underside of the rear deck.
Removing the front door speakers
On both the base and Harman Kardon systems, the front door speaker array consists of woofers at the base of the door panels, and a mid-range/tweeter combo in the center. The crossover points for the system are not known (by us, anyway) at this time. If you know more, please share your knowledge in the comments section below.
The woofer can be replaced with 5-1/4" or 6-1/2" speakers with the help of mounting brackets that are included with your Crutchfield speaker purchase. The 2-1/2" mid-range speakers are mounted with the tweeters in the grille, which is attached to the door panel itself.
Same-size replacements for the mids are not available, but smaller speakers can be secured in this space with the help of a universal backstrap. A wiring harness is not available for this location, so you'll have to splice, solder, or (better, easier idea) use a set of Posi-Products speaker connectors.
Getting to the woofer and the mid involves removing the door panel. This is relatively light duty, requiring little more than some panel and Torx screw removal.
Detailed, illustrated instructions for this disassembly process can be found in the Crutchfield MasterSheet that's included free with your stereo or speaker purchase. The key element here is to work carefully and patiently when removing the plastic door panels.
The tweeters are mounted on the door panels (Crutchfield Research Photo)
Removing the tweeters
To remove the tweeters, you'll start by removing two retaining clips from the trim on the front edge of the door. Pull that edge trim out just enough to access the tweeter then remove the Torx T30 screw that secures the tweeter/bracket assembly. Pull the tweeter out and cut the wires close to the terminal. Obviously, having done that, you'll need some more Posi-Products to connect the new tweeter to the factory wiring. You'll also need a universal backstrap to secure the tweeter in place.
Tools needed: Phillips screwdriver, small flat blade screwdriver, panel tool, Torx T30 driver, Torx T20 driver
Replacing the speakers in this space is a lot easier than folding people into it (Crutchfield Research Photo)
Removing the rear side speakers
This coupe's rear seat area is rather cozy, but the people you wedge into it will at least be able to enjoy the music coming from the side panel speakers as they slowly lose all blood flow to their feet.
Getting to these 2-1/2" mid-range speakers is one of the easier things you'll do on a 3 Series, but with no wiring harness or mounting bracket available for this location, you'll need Posi-Products speaker connectors and a pair of universal backstraps to install your aftermarket speakers.
To get to them, you'll remove two Torx T20 screws under the armrest, then pry out at the top front edge of the panel to release the retaining clips. Next, you'll need to pull the panel out juuuusst enough to get your hand behind the panel and turn the speaker counter-clockwise until it's loose. Then, disconnect the harness and pull the speaker out.
You'll need to apply the right mixture of strength and finesse to do this job, but if you're careful and patient, you'll be fine.
Tools needed: Torx T-20 driver, 8mm socket, ratchet and extension, panel tool, Phillips screwdriver
The rear deck speakers are pretty easy to deal with, but you'll need to drill new mounting holes (Crutchfield Research Photo)
Removing the rear deck speakers
The rear deck speakers are the same size as the woofers in the front door, so you can replace these with 5-1/4" or 6-1/2" aftermarket models, too.
These top-mount speakers are pretty easy to reach and replace, but there is a bit of drilling involved. Start by prying off the cover on the child seatbelt anchor, then remove one exposed 12mm bolt. Next, you'll pry up the rear speaker grille, then remove the foam ring around the speaker. Remove the three 8mm screws securing the speaker, disconnect it, and set it aside.
Place your new speaker in that spot and use it as a template for marking where you'll be drilling the new mounting holes. Remove the speaker and use a 1/8" bit to drill the holes. Use Posi-Products connectors to join the new speaker to the factory wiring, then secure it with the screws supplied. Test it out, make sure it works, then replace the grilles.
Drilling a few holes isn't tough, but you are drilling holes into a BMW (Your BMW), so be careful, wear eye protection, and pay attention to underlying wiring, structures, and safety devices. Check your drilling depth and location to avoid damaging your car. Also, the "screws supplied" line used above isn’t always true, so check the box to make sure they're in there. If they aren't, hie thee to a hardware store.
Tools needed: Torx T-20 driver, 8mm socket, ratchet and extension, panel tool, Phillips screwdriver, cordless drill and 1/8" bit
Read our Car Speakers Buying Guide for more information.
The Harman Kardon system includes a deck-mounted subwoofer assembly (Crutchfield Research Photo)
More bass in your BMW 3 Series
The Harman-Kardon system adds two 6"x9" subwoofers in a plastic enclosure mounted to the underside of the rear deck between the speakers. To replace them, you'll first need to remove the enclosure from the trunk. To do so, you'll remove four 8mm screws from the bottom of the enclosure; then pry down at the rear of the enclosure to release two plastic retaining clips. Pull the enclosure out and disconnect the amp harness to remove. Once that's out of the car, you'll remove four Torx T20 screws from each speaker.
You can replace these subs, which are powered by a sub amp behind the driver's side trunk trim, with a variety of same-size, 5-1/4" or 6-1/2" subs. A speaker adapter bracket is required for the smaller models, and it's included free with your speaker purchase. Though the enclosure is rather thin, the cavities in the deck will hold a good sized magnet, so you'll have a good selection of subs to choose from.
If that's not quite enough bass for you, or your car wasn't equipped with factory subs, you have a variety of options for adding bass. If you're thinking about a component subwoofer in a box, your available space is 29"W x 15"H x 30"/38" D. It's not a vast space, but that's plenty of room for some serious bass power.
If you like bass, but still need room for things like groceries and luggage, a compact powered subwoofer is a great choice for this car. You'll get plenty of thump without losing your entire trunk.
Tools needed: small flat blade screwdriver, Torx T-20 drivers, panel tool
Learn more about building a bass system in our Car Subwoofer Buying Guide.
A portable GPS with a built-in dash cam is great for track days.
Other options for your 3 Series
There are plenty of other ways to improve your 3 Series. Here are some of the ways Crutchfield can help.
A big screen nav receiver isn’t going to fit into the dash, but that doesn't mean you have to be directionless. We offer a wide array of portable GPS models that will fit nicely on the dash when you need them and store easily in a purse or go-bag when you don't. That's kind of a handy thing when you're parking on the street or in unattended garages.
Adding an aftermarket amplifier will really help you get the most out of your new speakers. The 3 Series isn't short on cargo space, but if you still use it for family duties, a compact Class D amp would be the best choice. Learn more about adding amps to your system in our Car Amplifier Buying Guide.
If you like your music as pure as your driving experience, hearing more stereo and less road noise is a good start. The Dynamat Xtreme Door Kit is the perfect way to seal in sound. This heavy-duty insulating material is easy to install, and it really makes a difference.
Installing a security system in a BMW 3 Series isn't easy (security systems rarely are), but it's less complicated than it could be. Our Crutchfield Advisors can help figure out what you need to get the job done, but we usually recommend taking your car (and your new gear) to a professional installer.