The basic connection: what you're actually doing

A subwoofer is a speaker that plays only the lowest sounds — bass and rumble — and it connects to your receiver or amplifier with a single cable. The subwoofer has its own power cord and amplifier built inside, so you do not need to run it through your main speaker system. You plug the subwoofer into power, run one audio cable from your receiver to the subwoofer's input, and turn it on. That is the entire physical setup.

The reason subwoofers exist is that regular speakers struggle with very low frequencies. A subwoofer handles those frequencies better, which means your main speakers can focus on the middle and high sounds, and the whole system sounds clearer. You will notice the difference most in movies, music with heavy bass, and video games.

Key Takeaways

  • A subwoofer connects to your receiver with a single RCA cable, which is the same type used for older audio equipment and looks like a thin cord with a metal ring on each end.
  • Most receivers have a dedicated subwoofer output port labeled "Sub Out" or "Subwoofer," making the connection straightforward even if you have never done this before.
  • After plugging in the cable, you will need to adjust the subwoofer's volume dial and crossover setting so it blends with your main speakers instead of overpowering them.
  • If your receiver has no subwoofer output, you can still connect one using a Y-splitter cable or by running the cable from your amplifier's pre-out ports instead.

Finding the right cable and ports

You need an RCA cable — a thin audio cable with a metal ring connector on each end, usually colored red or white. Most electronics stores sell these for under ten dollars. The cable connects to the "Sub Out" or "Subwoofer" port on the back of your receiver, which is usually labeled clearly and sits near other audio outputs. On the subwoofer itself, look for a port labeled "Input" or "LFE In" (Low Frequency Effects Input). Plug one end of the RCA cable into the receiver's subwoofer output and the other end into the subwoofer's input port.

If your receiver does not have a dedicated subwoofer output, check whether it has pre-out ports — these are usually a pair of RCA ports labeled "Pre Out" or "Amp Out." You can use these instead. If your receiver has neither, you will need a Y-splitter cable, which takes the signal from your receiver's main audio output and splits it so the subwoofer can receive part of it. A Y-splitter costs five to fifteen dollars and works with any receiver.

Powering on and locating the volume controls

Plug the subwoofer into a wall outlet or power strip. Most subwoofers have a power switch on the back or a button on the front. Turn it on — you should see a light indicator, usually red or blue, appear on the subwoofer's front panel. This light tells you the subwoofer is receiving power and waiting for an audio signal.

On the front or back of the subwoofer, you will find a volume dial or knob labeled "Level," "Volume," or "Gain." This controls how loud the subwoofer plays. Start by turning this dial to the middle position — around 50 percent. You will adjust this after you test the sound. Do not crank it to maximum right away, because a subwoofer set too loud will overpower your music and movies instead of blending with them.

Setting the crossover frequency

The crossover is a dial that tells the subwoofer which sounds to play. It is usually labeled "Crossover," "Freq," or "Hz" and sits on the back of the subwoofer. The crossover frequency is measured in hertz (Hz), which is how many sound waves per second. A setting of 80 Hz means the subwoofer will play all sounds below 80 Hz and ignore everything above that.

For most home setups, set the crossover between 80 and 120 Hz. If your main speakers are small or sit in a small room, use 100 to 120 Hz. If your main speakers are large or you have a big room, use 80 to 100 Hz. You can adjust this dial later if the bass sounds wrong — too much bass means lower the crossover, and too little bass means raise it. Start in the middle of your range and fine-tune after you listen to a few songs or a movie scene with bass.

Testing the connection and adjusting volume

Play something with bass — a movie with action scenes, a music track with drums, or a video game. Listen to where the bass is coming from. If it sounds like the bass is coming from the subwoofer itself (a separate "boom" sound), the volume is too high. If you cannot hear the bass at all, the volume is too low or the crossover is set wrong. Adjust the subwoofer's volume dial up or down by small amounts — quarter turns at a time — until the bass feels like it is part of the overall sound, not a separate thing.

The goal is for the subwoofer to be invisible. You should feel the bass and hear it, but you should not be able to point to the subwoofer and say "that is where the sound is coming from." If you can point to it, lower the volume. Once the volume sounds right, you are done. The subwoofer will stay at that setting and work automatically whenever your receiver sends it a bass signal.

Troubleshooting when you hear no bass

If you plugged everything in and hear no bass at all, check these things in order. First, make sure the subwoofer is powered on — look for the light indicator on the front. Second, check that the RCA cable is plugged all the way into both the receiver and the subwoofer. A cable that is halfway plugged in will not carry sound. Third, check your receiver's settings. Some receivers have a menu option that turns the subwoofer output on or off. Look in the receiver's manual or settings menu for "Subwoofer," "LFE," or "Bass Management" and make sure it is turned on.

Fourth, test with a different audio source. If your receiver is connected to a streaming device, a cable box, or a game console, try a different one to see if the problem is with the receiver or the source. Fifth, turn the subwoofer's volume dial all the way up temporarily — just to test. If you hear bass at maximum volume, the subwoofer works and you only need to adjust the volume down to a normal level. If you still hear nothing, the cable may be bad. Try a different RCA cable if you have one available.

Wireless subwoofers and other connection types

Some newer subwoofers connect wirelessly instead of with a cable. These use WiFi or a proprietary wireless signal to communicate with your receiver. If your subwoofer is wireless, you will not need an RCA cable. Instead, you will pair the subwoofer to your receiver the same way you pair a Bluetooth speaker — usually by holding a pairing button on both devices for a few seconds until they recognize each other. Check your subwoofer's manual for the exact pairing steps, because each brand does this slightly differently.

A few older receivers use different connection types, such as XLR cables or speaker-level connections. These are less common in modern equipment. If your receiver or subwoofer has ports that do not look like the RCA connectors described above, check the manual that came with the subwoofer or receiver. The manual will show you exactly which ports to use and what cable type you need.

Frequently Asked Questions

Can I use any RCA cable, or does it have to be a special subwoofer cable?

Any RCA cable works. Subwoofer cables are sometimes thicker or shielded to reduce interference, but a standard audio RCA cable will connect and function the same way. If you already have an RCA cable at home, you can use it. If you need to buy one, a basic cable under ten dollars is fine.

What if my receiver does not have a subwoofer output port?

Use a Y-splitter cable connected to your receiver's main audio output, or connect the RCA cable to the pre-out ports if your receiver has them. Both methods work and cost very little. Your subwoofer will still receive the bass signal and play it correctly.

Should the subwoofer be in the same corner as my TV, or can it go anywhere?

The subwoofer can go almost anywhere in the room — corner, side wall, or even behind furniture. Bass frequencies are hard to locate by ear, so placement matters less than it does for regular speakers. Put the subwoofer where it fits and sounds good to you. If the bass sounds boomy or uneven, try moving it a few feet and listen again.

How loud should the subwoofer volume be compared to my main speakers?

The subwoofer should not be louder than your main speakers. Start at 50 percent volume and adjust up or down until the bass blends with the rest of the sound. If you have to turn it down more than halfway, that is normal. If you have to turn it all the way up and still cannot hear bass, the crossover setting is probably wrong.

Do I need to turn the subwoofer off when I am not using it?

You can leave it on or turn it off — both are fine. Many people leave subwoofers on all the time because they use very little power when no bass signal is being sent. If you want to save power, turn it off when you are done listening. Some subwoofers have an auto-off feature that shuts them down after a period of silence.