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How to Add a Subwoofer to Your Car Stereo

by Staff Writer


Things You Need:

  • Screwdrivers
  • Long-nose pliers
  • Wire stripper
  • Fusible power cables
  • RCA cable
  • Blade connectors
  • Amplifier
  • Subwoofer speaker(s)
  • Variable speed drill

If you're ready to take your car audio experience to the next level, add a subwoofer to your car audio system. This article explains how to add a subwoofer to the speaker system of your car stereo, and if all the connections are correct, you will soon enjoy music in your car in a completely new way. Your car audio system will play sounds you never knew were there. Consider all of the instructions before you begin adding a subwoofer to your car stereo.

Installing a Subwoofer:

  1. For your safety, disconnect the car battery. Disconnect the negative cable first and then the positive. Always wear eye protection and be sure to read all safety materials that come with the tools you will be using.

  2. Take the fuse out of the amplifier. Put it in a safe place where it won't get lost.

  3. Connect a fusible power cable to the positive battery cable. Use a power cable gauged to handle the amperes your amplifier was designed for. A cable is usually included with the purchase of the amplifier. Find a way to connect the constant power cable to the positive battery cable from the inside of your car. Make sure the fuse is at the front of the car; if a short in the circuit occurs, you want to be able to reach the fuse quickly.

  4. A second cable must be spliced, linking the on/off power ignition switch and stereo to the amplifier. This will control when the powered subwoofer goes on. Read your vehicle user manual to discover what the wiring schematic looks like.

  5. Attach a ground wire from the amplifier to the frame of the vehicle. The frame is any metal part of the vehicle. Never ground the amplifier to the negative connection on the battery: It will drain the battery.

  6. Bolt the powered subwoofer to the floor of your trunk if you need it to stay secure. Subwoofers do vibrate significantly. Make sure you know where you are drilling to avoid any damage to any wiring or a gas line. Cover any additional wires. If there are any additional settings on the powered subwoofer, adjust them to allow it to operate at peak performance.

  7. Connect RCA cables from the subwoofer input to the stereo output or splice into existing stereo speaker wires. Make sure to connect the coordinating color scheme, left to left and right to right or positive to positive and negative to negative. Lay RCA cables or speaker wires along a path on the floor between the subwoofer and the stereo. The wires should be covered under the driver seat, under the inside trim along the doors or roof. For the best connection, solder and bond cables or wires with blade connectors.

  8. Replace the fuse in the amplifier. Check your engine compartment to make sure no wires are in danger of being stepped on or damaged. Check the trunk to make sure wires coming out of your subwoofer are secure and shielded from damage.

  9. Reconnect the battery and test the system. Reconnect the positive cable first and then the negative. Turn the car ignition to the "on" position and power on your stereo and amplifier. Play some music from the radio or a CD at low volume and then gradually increase it. Listen for excessive vibration from the subwoofer or distortion from the amplifier.

Car Stereo Tips:

  1. The output of the subwoofer should be the right one for the space where it will be placed. Too much air movement can limit sound and damage the speaker or blow out windows in your car. Don't place the subwoofer too close to the back seat of the car.

  2. The ohm rating must be identical in all connected speakers. Use 4 ohm with 4-ohm speakers and 8 ohm with 8-ohm speakers. Pairing different ohm ratings will cause static and deteriorate the quality of all the speakers.

  3. Make sure the settings on your subwoofer and amplifier are not high. Make sure you buy an amplifier that has a higher capacity than your speakers and subwoofer. Running the amplifier near its capacity degrades sound quality, and too much power will blow a fuse. You do not want to be distracted while driving and need to pull over just because the music stopped.

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