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Kenwood Speaker Upgrade

Although my previous speaker repair held up for several months, it was only a matter of time before that speaker (and others) started to fail. Crutchfield was having a great deal on Kenwood KFC-P708 component speakers (6.5" woofer + discrete tweeter), so I bought a pair to install in my car. Crutchfield car gear is great since it comes free with instructions and the mounting hardware to do the job.

The Passat has a tweeter located near the rear-view mirror, and the 6.5" woofer is near the kickplate. The door panels need to come off to swap out the old speakers.

Taking off the door panels reveals the Dynamat project from several months ago. I'm glad to see the Damplifier material survived the hot summer weather!

The front speaker cone had separated from the surround. Now is a good time to replace it.

To get the old speaker out, you need to drill out the four rivets that hold it in place. The proprietary VW speaker connector will need to be cut off with tin-snips so the wires can be fed into the speaker crossover box.

Here's a photo comparing the new Kenwood speaker (right) and the stock VW speaker (left). The Kenwood has a more durable rubber surround vs. the cracked foam surround on the VW.

Flipping the speakers over reveals an even more differences. The Kenwood has a much larger and heavier magnet which improves the efficiency of the loudspeaker. This will help me get the most SPL out of my stock headunit.

I soldered some long 18 AWG wire onto the speaker terminals and twisted the pair together. This helps to reduce common mode noise that otherwise could hop onto the line and cause the speaker to hum.

Unfortunately, the speakers did not fit quite right with the Crutchfield supplied baffles. To get them mounted, I marked and drilled smaller holes in the mounting area.

To install the speakers, I flipped the Crutchfield baffles upside-down, and fed deck screws from the front of the speaker into the sheet metal. On the first door, I tried sealing all the air gaps around the baffle with hot glue, but this step was largely unnecessary. It didn't improve sound quality substantially, so I didn't bother gluing the rest of the doors.

With the 6.5" speakers installed, it was time to turn attention to the tweeters. The stock tweeters are in series with a capacitor to act as a simile high-pass crossover. The Kenwoods employ a more advanced L-C crossover network that does a better job filtering low and high frequencies to the woofer and tweeter, respectively.

The tweeters in the front of the car are roughly the same size, although the Kenwood (on right) is heavier from having a larger magnet. I disassembled the Kenwood tweeter module and removed the metal grill so it would fit in the VW trim piece.

Hot glue is applied liberally to the trim piece to seal in the Kenwood tweeter. Speaker wires are soldered on and twisted together as well. The trim piece can then be reattached to the car door.

It's important to find a good location for the crossover that does not interfere with door operation or the power window mechanism. For the front doors, this turned out to be a good spot. When the speaker wires are connected to the crossover, note that the VW red/green and black wires go to the (+) terminal, and the VW brown/green and white wires go to the (-) terminal.

Because the crossover fits snugly when the door panel is reinstalled, I just secured it in place with some painter's tape. The door panel can be carefully reattached at this point while taking extra caution to make sure the rubber gasket in the door panel is pressed evenly around the woofer.

The passenger side door can be upgraded in the same manner as the driver side door.

After removing the door panels and tweeters from the rear seats, it's apparent how much of an improvement the new drivers are. The stock tweeters are smaller and are have a rubber dome. The new soft-dome Kenwood's produce high frequencies with significantly more clarity.

The woofer, tweeter, and crossover are installed similarly to the front seats. Because there is less room for the crossover here, I took the transparent plastic cover off. It's very important to pick a good spot for the crossover in the rear panels because my first attempt kept knocking the window off its track. Since the rear seat tweeters are located directly behind the driver and passenger's ears, I used the crossover to attenuate them to -4dB.

The stock headunit has enough juice to drive the 3 ohm Kenwood speakers to reasonable volumes without the amp overheating. The quality improvement of the speakers is instantly notable; bass has more definition, and the midrange is no longer tainted by low-quality rear tweeters. Great upgrade!


2x Kenwood KFC-P708 component speakers $119.98

Total $119.98