How to Wire Tweeters to Coaxial Speakers

How to Wire Tweeters to Coaxial Speakers

It might seem a daunting task, but knowing how to wire tweeters to coaxial speakers doesn’t require a pro.

Car audio enthusiasts often say coaxial speakers lack the high-end definitions and air that separate tweeters do. That’s why they install separate tweeters. But how do you do it without damaging your equipment?

Here’s how:


The Concept

Wiring Tweeters to Coaxial Speakers

To add wire tweeters to coaxial speakers, you have to install an external crossover. That’s connecting an amplifier to the input terminal. So, you set up one output to existing coaxial speakers and the second output terminal to newly installed tweeters.

All you need are a few tools, clear instructions, and careful application.


Gather Your Tools

You will need the following to get this show on the road.

We suggest grabbing your auto manual too. (It’s in the glove, right?) If you can’t find it, go here to see if there’s a copy. Any instructions that came with the tweeters may provide info during the tweeter installation, so keep those around as well.


The Process

Let’s get started!

Disconnect the Negative Terminal

Disconnect Negative Terminal Before Wiring Tweeters to Coaxial Speakers

Whenever you work on car audio equipment, the first thing you do is disconnect the battery. Here’s why.

  • There may be backup battery capacitors or sources. If not disengaged, electronic equipment can receive an unwanted voltage spike.
  • Reinstallation can create a voltage spike in your electronics.
  • Capacitors may still have a charge even if the car isn’t powered up.
  • There’s the possibility of static that leads to damage of audio equipment or in your ECU.

When disconnecting a car battery, disconnect the black or negative (-) terminal. Use the socket wrench to loosen the nut and move the cable to the side. Make sure it’s away from the terminal.

Note: A disconnected negative cable must never touch the positive (+) terminal. Mishaps like slipping wrenches have caused connections, resulting in short circuits, exploding batteries, and fires.


Picking a Location for Tweeters

car tweeter locations

Tweeters can go in a couple of places, like the sail panel or dashboard edges. Factory speakers are usually installed inside car doors, often at or slightly above knee level. Other locations include the dash, above the back seat in the rear deck, and in the kick panels under the dash’s side space.

Knowing where the coaxial speakers are helps determine where to put the tweeters. Audio experts recommend tweeters be near ear height. Others suggest mounting your tweeter within a foot of your coaxial. That way, you enable hearing your high and low frequencies near the same time.

The best spots for the tweeters are:

  • Sail panels: in the corner of the car door between the window and body
  • Dashboard outer edges
  • In the upper door
  • Between the windshield and car body, the region called the “A” pillar

You have two options for mounting tweeters: surface or flush. Surface mounting entails putting the tweeter atop a surface. The approach requires less work and modification but will make the tweeters more noticeable.

Flush mounts will be less intrusive and more attractive. It requires cutting a hole to ensure your new tweeters are at sit level with the interior panel.

“A” pillar installation needs a flush surface mounting. Flushing is best for door installations. The dash uses an angled surface and adjustable mounts to allow positioning the tweeter for the best sound.


Disconnect/Remove Coaxial Speakers

Remove Coaxial Speakers to Connect Tweeters

If you can see coaxial speakers on the rear or dash, carefully remove the grill and factory speaker. Foam or sealant may be keeping the speakers in place. Use the utility knife like a surgeon to cut them loose. Remove screws and disconnect wires with care.

Getting those coaxial speakers in your doors will need a little diligence. An older auto may require removing the window crank with a window clip remover or your screwdriver.

Modern cars have power windows. Remove the electronic control module that powers the windows. The device is often built into the armrest. Check the manual to make sure.

Now, you can remove the door panel. You may need to get out the trim panel remover tool in order to release some clips and screws.


Mount and Wire Tweeters

Mount and Wire Tweeters to Coaxial Speaker
Instagram/Car & Audio

Here are the methods for the varying mount options.

Surface Mount

For a surface mount to the “A” pillar, you need to drill a small hole. Run the wire to the tweeter. Now attach the tweeter to the surface mount. The last step is creating holes for the screws which stabilize the mount.

Flush Mount

Take your hole saw and, using the width of the tweeter, drill a hole in the door panel. Detaching the panel makes this easier. Run some wire to the tweeter and create the connection. Attach the tweeter to the base cap as instructed by the manufacturer.



install crossover

Aftermarket car tweeters usually come with inline crossovers. Check the tweeter manual to see if this applies to yours. If not, and you want high frequencies, follow the instructions for installing a crossover.


Testing New Tweeters

test car tweeter

Here are a few tips for making you know how to connect tweeters to speakers. Most issues are directly related to sound.

  • Disconnect and reattach a short piece of wire. Lightly touch the wire to an AA or 9-volt battery. You should get a crackling noise. If you do, the connection is the problem. If not, your tweeter is the issue.
  • If the tweeter works and you still can’t get sound, there could be a glitch in the crossover or amplifier.
  • Take a look at the ohm If the number’s too low, amplifiers can trip a circuit or blow a fuse.
  • If speakers aren’t mounted correctly, you’ll get a rattling or unpleasant buzz. Check the installation.



Knowing how to wire tweeters to coaxial speakers only requires a little patience and due diligence. You don’t need to be an audio or auto expert. This article will help you get your sonic pleasures.