How To Install A Subwoofer

What do I need to know before I learn how to install a subwoofer?

The First thing you need for an effective subwoofer installation is at least a basic understanding of Resistance and watts. Resistance is measured in ohms, think of a water hose as a wire. This wire is what carries power to a potential load (the subwoofer(s) in this case), when your amplifier is powered from your battery (12 volt car battery) it is intending on powering your load. Your car battery in this example would be the nozzle you use to turn on and increase the water. Now that we have a basic understanding of what needs to be done lets begin a real world scenario using this example.

When the nozzle is turned it turned (amplifier turned on) it sends water threw the hose (subwoofer wiring) and in turn powers the subwoofer (sprayer head). Subwoofer wiring techniques are all about how many subwoofers you are using and how much power each one can produce with the amplifier (nozzle) you are using.

What is resistance and why will it help me learn how to install a subwoofer?

Think of The Resistance (ohms) of a subwoofer as a person bending a water hose and making it harder for the water to come out. The more you bend, the less water comes out of the hose at the other end. The force in which you bend is resistance, resisting the the flow of water.

To put the example above in perspective, the hose is the wire and your bending force is the voice coil of the subwoofer.

Each subwoofer has a specific set of parameters, watts ratings@rms/peak), number of voice coils, and resistance at the voice coils. Resistance is one of the most important things to consider during subwoofer installation.

What are voice coils and how will they help me learn how to install a subwoofer?

Most subwoofers after 2010 were made with 2 voice coils, having two voice coils does nothing more than allow you to wire the subwoofer at different power levels. All subwoofers have at least one voice coil which is indicated by the terminals on the amplifier labeled (-) and (+). At the bottom of each subwoofer you’ll see a pretty big metal contraption, usually circular, this is actually a magnet.

This magnet uses the voice coil to power and un-power itself depending upon the situation, When positively charged electrons flow into the (+) terminal of the subwoofer the magnet pushes the woofer cone up. When negatively charged electrons go threw the (-) terminal of the subwoofer the magnet pulls the woofer cone back down towards the magnet.

What are watts and how will they help me learn how to install a subwoofer?

A watt is a measurement of energy conversion with respect to time. This is something that confuses most installers no matter how long they’ve been installing and i’d rather not confuse you going into depth explaining electricity and theory to you. Your amplifier takes in DC (direct current) from your battery and converts it into AC (alternating current) and your amplifier creates the power in watts to send to your subwoofer.

How do I match a subwoofer to an amplifier?

The main factors to understand when searching for a subwoofer and amplifier are the watt output of the amplifier, the amount of channels and the resistant stability. The subwoofer should match in terms of resistance and watt output. Ill use my favorite car subwoofer and amp package as an example:

If I have a 500 watt(rms) one channel(mono) amplifier that is rated at 4 ohms I need a subwoofer that is 4 ohms with atleast one voice coil. The Rockford Fosgate R500X1D would be the perfect amplifier for this scenario because it is 4 ohm stable and has an output of 4 ohms into a 4 ohm sub woofer. In terms of subwoofer installation I know from experience the Rockford Fosgate 12 inche P3 works perfectly for this amp and runs 500 watts RMS at 4 ohms.

This How-To page is to help you understand subwoofer installation and does not explain full amplifier installation, If you would like to learn how to fully install an amplifier from beginning to end visit our amp installation page.

 How do I wire my subwoofer?

Now the wiring begins. Now that you have paired your subwoofer with your amplifier you must decide how the wiring from the speaker terminals must be done. If you have a 1 channel (mono) amplifier and a closely rated subwoofer lite the recommended sub and amp from rockford fosgate mentioned above it will make things much easier. I’ve created a few steps below to help you to install a perfectly matched sub woofer and amplifier in your subwoofer installation goal. If you have a more advanced set up then I’d recommend using the subwoofer wiring wizard from my guys over at 12volt.

How to install a subwoofer in steps

Step 1)

Locate your speaker terminals on your amplifier. You will see two holes with a single screw drilled into them. If your amplifier has more than one set of speaker terminals there is a possibility it is a 2 channel amp and you would need to use the subwoofer wiring wizard to properly wire this amp. if it is a true one channel (mono) amplifier you may either pair of speaker terminals to connect to your subwoofer.

Step 2)

Connect your speaker wires to the proper subwoofer terminals. There will be a negative (-) and positive (+) terminal. run your negative wire from your amplifier to the negative subwoofer terminal (-). Usually black in color.

Step 3)

Run your Positive wire from your amplifier to the positive terminal on your subwoofer (+). Usually red in color. If you have another set of terminals on the opposite side of the amp you do not need to use them as long as the subwoofer is stable at 4 ohms.

Step 4)

Make sure your “gain” and or “bass boost” nobs are turned all the way down to “0” so that you dont damage your subwoofer or amplifier.

Step 5)

Check to ensure your wiring is correct, power on your vehicle and start tuning your system!