You don't need a new radio to get real bass. Most factory systems take a sub just fine, and you keep your screen, CarPlay and wheel buttons. Here is how we add a subwoofer to a factory radio in the bay.
- Pick a route
- Pick a spot
- What you need
- 1. Run power
- 2. Tap the signal
- 3. Remote
- 4. Connect the sub
- 5. Set it
- Bass fade fix
- Mistakes
Three Ways to Do It
A powered sub has the amp built into the box. It is the fastest install and most take speaker wires directly. The Rockford Fosgate P300-10 is a good example, with a sealed 10-inch box, a 300W amp and a remote bass knob.
For the most bass, use a separate monoblock amp and sub with a line output converter. Some amps have high-level inputs, so you can skip the converter.
Pick Your Spot First
Where the sub goes decides which sub you buy. Trunks and hatches fit a full box. Slim powered subs slide under a seat. Trucks get the most from a vehicle fit box behind or under the rear seat.
SoundQubed HDS2 12" PoweredShop now →
Audiopipe APLP-1030 10"Shop now →
Soundstream USB-10DLShop now →
Power Acoustik PUB-10LShop now →
Audiopipe APSB-12112PX PackageShop now →
What You Need
- Sub and ampOr one powered sub.
- Amp install kitPower, ground, fuse and remote.
- Line output converterIf your amp lacks high-level inputs.
- RCA cablesFrom the converter to the amp.
- Speaker wireFrom the amp to the sub.
- MultimeterTo find the factory wires.
Step 1 Run Power and Ground
Run the power wire from the battery to the amp with a fuse within 18 inches of the battery. Ground the amp to bare metal close by. Powered subs wire up the same way, just with a smaller kit.
Every step is in our guide on how to install a car amplifier.
Step 2 Tap the Factory Signal
Find a pair of speaker wires with full bass. Rear door or rear deck speaker wires are a common choice, since they are easy to reach. Connect them to your converter or to the amp's high-level inputs, positive to positive. Have a factory amp or factory sub? We walk through it in how to install a line output converter.
Step 3 Hook Up the Remote
Factory radios have no remote wire, so the amp needs another turn-on source. Many converters and powered subs sense the audio and turn on by themselves. If yours doesn't, use an add-a-circuit on a fuse that only has power with the key on. Never use constant 12 volts.
Step 4 Connect the Sub
Run speaker wire from the amp to the sub, positive to positive. Make sure the final ohm load is one your amp is stable at. Not sure how to wire the coils? Read how to wire subwoofers or check a match with Amp Matchmaker.
Step 5 Set the Level and Crossover
Set the amp's low pass filter to about 80 Hz and turn the subsonic filter on if your amp has one. Set the converter level first, then the amp gain, with the radio at about three quarters volume. Our guide on setting amp gain covers it step by step.
Fix Bass Fades When You Turn It Up?
Many factory radios cut bass as the volume goes up, to protect small factory speakers. Your sub gets weaker right when you want it most.
A bass restoration processor puts that missing bass back before it reaches your amp. A bass knob up front lets you turn it up or down for each song.
Most of these units do double duty as a line output converter, so you may not need a separate one.
Common Mistakes We See
- Tapping tweeter wires, so no bass gets through
- Using constant 12 volts for the remote
- No fuse at the battery
- Wiring below the amp's stable load
- Gain cranked to fix a weak signal
- Skipping the subsonic filter on a ported box
Gear Up to Add Bass
Everything in this guide is in stock and ready to ship.
Running the amp power wire? Here is how to run power wire through the firewall. Building your own box instead? Here is how to build a subwoofer box, or design one free with Box Buddy. Lights dim when the bass hits? Read why headlights dim with bass.
