The "5.0 Mustang" magazine project car

Adding custom sound while keeping the factory look


Ken Nail

Ken Nail has written about car audio for Crutchfield since 2003, after four years as Crutchfield Sales Advisor, and 10 years as a music teacher. He's an avid music listener, whose favorites are classical and film music. When not chained to a desk, Ken spends most of his time training for triathlons and marathons, and likes getting outside for backpacking, downhill skiing, and bicycle touring. He attended West Virginia University, where he received a Master's Degree in Music Performance and a Bachelor's Degree in History.

More from Ken Nail

Talk about a dream assignment! When the now-defunct (and much-missed) 5.0 Mustang magazine wanted a killer audio system installed in their Mustang project car back in 2002, Crutchfield Project Car Designer Warren Hawkins was given the job. His mission? Pick the best components and put in a sound system that matched the performance and good looks of the car.

There were some ground rules, though. The system's audio performance needed to stand out, but the components had to blend in. Speakers were to be located in the factory locations, and the amps and subs needed to be as unobtrusive as possible. As you'll see, Warren came up with some very smart solutions.

Some of the gear we used in this installation is no longer available, but we've provided links where appropriate to help you get the gear you need for your own 5.0 Mustang car audio project.

2001 Ford Mustang coupe

The "5.0 Mustang" magazine Ford Mustang GT coupe

The gear

As a senior tech at Crutchfield, Warren knows the best equipment to use. For this Mustang, he chose an Alpine DVD/CD/MP3 receiver with three sets of 4-volt preamp outputs, plenty of sound-shaping controls, and a motorized 7" LCD monitor. Warren also added an Alpine satellite radio tuner.

Speaker-wise, Warren installed Polk MOMO 6-3/4" components front and back. The separate tweeters and external crossovers allowed him to mount the tweeters separately from the woofer and achieve optimal stereo imaging and separation. Warren relied on his installation expertise to customize Mustang's 6" x 8" openings for the 6-3/4"component sets.

To power the Polks, he chose a Rockford Fosgate four-channel amp, cranking 110 watts RMS of solid power at a clean 0.05% THD. And, for booming bass, Warren used 10" Kicker Solo-Baric L7 subs powered by another Rockford Fosgate amplifier.

Alpine receiver in a Ford Mustang

The receiver fits neatly in the dash, and the polished metal switch plate adds a custom touch.

Receiver installation

To fit the Alpine receiver into the larger stock opening, Warren used an off-the-shelf mounting kit, modified to hold a metal panel in the space above the receiver. The panel was machined and polished to match the other dash accents, then fitted with switches.

The result is a clean-looking dash installation that stays true to the spirit of the project. With the screen retracted, you'd have to look twice to notice anything out of the ordinary. When you're ready to show off, pop out the motorized 7" screen and cue up some video!

Alpine receiver

The motorized 7" screen pops up when needed, and looks terrific.

Since the existing MACH-460 sound system was scrapped for the installation, Warren didn't have to bother with connecting the receiver into the Ford amplifiers. Power and ground connections were made behind the dash, as well as preamp-level hookups to the amps and the XM tuner connections.

polk tweeters

Warren built the custom sail panels to hold the Polk/MOMO tweeters. The location ensures great sound and superb looks.

Front speaker installation

Installing the 6-1/2" Polk MOMO components into door openings designed for 6" x 8" speakers took some creativity. The woofers have rather large magnets, so Warren started by fabricating mounting plates out of light, strong 1/2" birch plywood — an ideal material for this kind of job. The mounting plates, which bolt into the factory mounting holes, act as lift rings to provide clearance for the magnets. The crossovers for the components were tucked underneath the dash.

The tweeter mounts Warren created are real works of art. The Mustang's stock MACH-460 system already had tweeters in the sail panels, but Warren discarded these in favor of new, hand-built enclosures. Starting with a base layer of birch, successive layers of fiberglass were built up into the proper shape, covered with black vinyl and installed in the factory location. The tweeters fit perfectly and are at an ideal height for accurate stereo imaging.

Rear speaker Installation

The rear deck speakers presented a few challenges. The original 6" x 8" speakers and MACH-460 amps were mounted on a panel secured to the underside of the rear deck. Warren disconnected and discarded this original equipment, then made 1/2" birch mounting plates to hold the Polk/MOMO components.

The new panel and speakers fits snugly under the existing rear deck grilles, and the wooden mounting panels are covered in black vinyl. The result is an installation that looks stock, but sounds much better!

solo-baric subwoofers in a ford mustang

The twin subs may look cozy in their black and yellow vinyl-covered box, but they turn fierce when the amp juices them up with 1000 watts.

Installing the subs

The Kicker Solo-Baric L7 subwoofers pound hard and still supply deep, tight response in small enclosures — an important consideration with the limited space available in the Mustang's trunk.

The simple, square enclosures are made using 3/4" birch sheets held together with 2-1/2" wood screws and wood glue. Boxes are usually made from MDF, but Warren found the birch to be very strong and dense, so box vibration wasn't a problem. Following Kicker's recommendations, each box is stuffed with a half-pound of Polyfill.

The boxes were covered with 1/2" of foam padding, which was then covered by yellow vinyl that matches the Mustang's exterior. A sleek black vinyl-covered panel holds the distribution block between the sub boxes.

ford mustang amps

The vinyl -covered amp rack displays the Rockford Fosgate amps behind a plexiglass panel. Four 12-volt fans keep the box ventilated.

Amplifier installation

In keeping with the "stealthy" installation concept, the Rockford Fosgate amps are behind the rear seats, out of sight until the seats are folded down. The Plexiglas panel is framed by yellow and black vinyl, and for an extra custom touch, Warren backlit the panel with 6" blue neon tubes. The Crutchfield logo sandblasted onto the Plexiglas glows blue when the lights a switch is flipped in the cockpit.

The look is cool, but if the amps get hot, they're not going to work. Warren solved that problem by drilling ventilation holes into the back of the amp enclosure and installing four 12-volt fans.


The right kind of cable is essential to getting max performance out of any stereo system. Warren started at the battery with 1/0 gauge cable for better power flow. The cable runs to the distribution block located between the sub boxes and splits off into two 4 gauge cables routed to each amp, with a third cable providing power to the head, XM tuner, fans, and lighting. Protection is provided by a 200-amp fuse in the engine compartment.

To ensure steady power flow, 60 amp fuses protect the distribution block. A one-farad capacitor is installed out of sight behind the amps. Patch cables run from the receiver to the amps, and more speaker wire connects the component speaker sets and sub boxes.


Crossover settings for the system were made at the amps. The subs are crossed over at 100 Hz low pass, and the component sets are dialed in at 100 Hz high pass.

Warren added some clever tweaks to the Polk speakers. The components' crossovers have a Selectable Tweeter Output Level feature. For the front speakers, this is set to "0 dB," and in the back, to "-6 dB." Also, the "mid-range extension" switch on the front crossovers is set to "on." This allows more high frequencies to flow to the front woofers. The result is a better imaging in the front end, since there are more high frequencies there.

If you've checked out the photos of the vehicle, you may wonder where the satellite radio antenna is hiding. Although XM doesn't recommend it, Warren placed it on the back deck between the speakers, which seems to have worked out fine.


Overall, the system Warren put together for this car proves that quality components and fine craftsmanship can produce a system that sounds extremely good without going to extremes.

Find what fits your car