How to Install a Powered Subwoofer

by Blaze Johnson

Installing a powered subwoofer in your vehicle will provide a substantial improvement in low-frequency sound reproduction. Powered subwoofers feature an integrated amplifier, speaker driver and custom enclosure, designed for maximum performance. In addition to being an “all-in-one” solution, using a powered subwoofer will eliminate much of the research and guesswork associated with installing the needed components separately.

1

Open the vehicle's hood and disconnect the black-colored negative battery cable from the battery. Set it aside and out of the way.

2

Determine the appropriate mounting area for the powered subwoofer; ensuring the mounting area allows for adequate ventilation needed to cool the integrated amplifier. Consider mounting the subwoofer within the trunk or cargo area. Although low-frequency bass sounds are less directional than higher frequencies, the location of the subwoofer may have an impact on performance.

3

Remove the required interior trim molding, located on the same side as the vehicle's battery, using an appropriate size and type screwdriver. Examine the underside of the dash panel and locate an existing wiring hole that leads to the engine compartment.

Wiring

1

Route the large gauge red-colored amplifier power cable through the existing wiring hole. If you cannot find an existing wiring hole in the firewall, drill an appropriately sized hole and add a rubber grommet to accommodate the power wire; be careful not to damage surrounding components when drilling.

2

Route the power cable to the battery area, but away from heat sources and moving mechanical parts.

3

Strip 3/8 inch of insulation from the power cable end and crimp on one of the ring connectors supplied with the amplifier kit. Cut the cable 1 foot or less from the ring terminal and strip the insulation from both of the newly formed ends. Secure both cable ends to the fuse holder supplied with the wiring kit.

4

Route the power cable underneath the carpet or trim molding to the mounting area for the subwoofer. If your vehicle does not feature a rear-mounted power antenna with easy access to the turn-on lead, you must remove the stereo from the dash to connect the small gauge “REM” turn-on lead supplied with the wiring kit to the radio's switched power wire; refer to your vehicle's repair manual for specific radio removal instructions and wiring diagrams. If you have an aftermarket car stereo with one or several RCA outputs, remove the radio, the interior molding opposite to the power cable and route the RCA cables from the subwoofer mounting area to the rear of the head unit.

5

Connect the RCA cables to the rear of the head unit and reinstall the stereo. Certain aftermarket head units may include RCA outputs specifically designed for subwoofer use. If you are connecting the subwoofer to an original factory stereo, connect the supplied high-level signal wiring harness to the appropriate left and right speaker wires using wire splice taps.

6

Connect the remote turn-on lead to the appropriate switched lead for the rear-mounted power antenna, if equipped, using the vehicle repair manual as a guide. Use this connection option for the subwoofer's remote turn-on lead to avoid removing the head unit when dealing with a factory stereo.

7

Mount the subwoofer to the designated area. Consider securing the subwoofer to the vehicle with self-tapping screws to avoid damage to the unit or possible injury during a collision.

8

Examine the mounting area and locate a suitable ground connection for the negative cable. Cut the ground cable to the appropriate size and install ring terminals on both ends of the cable. Install a ring terminal on only one end of the ground cable if the subwoofer unit includes setscrew-type power connections.

9

Install the negative cable to a suitable metal ground point on the vehicle using a drill and self-tapping screw. Use a wire brush or steel wool to remove any paint on the ground connection area before making the ground connection to the vehicle.

10

Connect the RCA cables or high-level signal wiring harness to the subwoofer unit, followed by the ground, positive and remote connections. Install the supplied fuse into the power cable fuse holder, located near the battery.

11

Connect the power cable to the battery. Vehicles that use side-post battery connections may require a special post adapter to connect additional cables to the battery. Batteries that use clamp-style battery connectors do not require an adapter.

Testing

1

Check the wiring connections and reconnect the negative battery cable. Adjust the subwoofer's “gain” control to the lowest setting.

2

Turn on the vehicle's stereo and adjust the volume to the highest setting, before the point of audible distortion.

3

Adjust the "gain" setting on the subwoofer in an incremental fashion, before the point of audible distortion. When making adjustments to the gain, crossover or other settings, consider using test music that includes a great deal of dynamic bass.

4

Turn off the stereo and reinstall any remaining interior components previously removed to complete the installation.

Tip

  • check Check What wattage your amp and subs are and make sure your head unit can handle it.

Warning

  • close Always make sure the battery is disconnected not only for your safety but for your cars safety.

Items you will need

References

About the Author

In the spring of 2008, Blaze Johnson decided to share his expertise through writing. He studied business administration at a local community college and runs his own driveway mechanic service, specializing in computer-controlled vehicles and custom car audio installs. Johnson also serves as the de facto computer repair person for his family, friends and coworkers.