How to Test a Subwoofer

The quickest way to test a subwoofer is to play a low test tone (around 40–60 Hz) and a slow bass sweep through your system and listen at your seat. If the sub is silent, the problem is almost always power, connection or a setting in your receiver or soundbar rather than a broken subwoofer.

Step 1: Play a bass test tone

1. Open our bass & subwoofer test on a device connected to your system.
2. Start with a low volume and press 50 Hz. You should hear and feel a deep, steady hum from the subwoofer.
3. Run the Subwoofer sweep (15 → 120 Hz). Listen for where the bass starts, any rattles, and spots where it becomes much louder or quieter.
4. Put your hand on the subwoofer cabinet or near the port. You should feel it move air at low frequencies.

Phone and laptop speakers cannot play these tones, so make sure the sound is actually going to your sound system (HDMI, optical, Bluetooth or a cable to the receiver).

Step 2: Subwoofer not working? Check power first

• Most home subwoofers are powered and need their own power cable. Check the switch on the back and the power LED.
• Many subs have Auto/standby mode and switch off after a few minutes of silence. They wake up only when they detect a signal. For testing, set the switch to On.
• If there is no light at all, try another socket and check the fuse on the back panel if your model has one.

Step 3: Check the connection

• AV receiver: use a single RCA cable from the receiver's SUB OUT / PRE OUT SUB to the subwoofer's LFE IN (or the left/"mono" LINE IN).
• Stereo amplifier without a sub output: use the sub's speaker-level (high-level) inputs, wired from the amplifier's speaker terminals.
• Wireless subwoofer with a soundbar: re-pair it using the pairing button on the sub and the soundbar remote or app – they often lose their link after a power cut.

Try a different RCA cable – they fail more often than subwoofers do.

Step 4: Check receiver or soundbar settings

• In the speaker setup menu, Subwoofer must be set to Yes or On.
• Set your main speakers to Small and the crossover to 80 Hz (a common starting point). If the main speakers are set to Large with no sub output for music, some receivers send little bass to the sub.
• Check the subwoofer level in the receiver is not set to the minimum, and that a "Pure Direct" or "Direct" mode is not switching the sub off.
• When a receiver handles the crossover, turn the crossover knob on the sub to its highest setting or LFE so the two do not fight each other.

Step 5: Set the subwoofer level and phase

1. Sit in your normal listening position and play the 50 Hz tone or music with steady bass.
2. Adjust the sub volume so the bass blends with the main speakers – you should hear deep bass, but it should not be obvious where it comes from.
3. Switch the phase between 0° and 180° (or turn the dial) while playing a tone near the crossover, around 80 Hz. Keep the setting that sounds louder and fuller at your seat.

Step 6: Check placement

Room acoustics cause big peaks and dips in bass. If the sweep shows a booming note or a near-silent spot, move the subwoofer. Corners give the most bass but also the most boom. A popular trick is the "subwoofer crawl": put the sub at your seat, play the sweep, crawl around the room to find where the bass sounds smoothest, and place the sub there.

Step 7: Test the driver itself

If the sub has power, a good connection and correct settings but still makes no sound or only buzzes, the driver or the built-in amplifier may be faulty. For passive and car subwoofers, disconnect the sub and measure the voice coil with a multimeter: a 4 Ω driver should read around 3–3.5 Ω. "OL" or infinite means the coil is open (blown). Dual voice coil subs have two pairs of terminals – test each pair. Read more in our blown speaker guide.

Car subwoofer not working?

• Check the amplifier's power light, the fuse near the battery and the fuse on the amplifier.
• Make sure the blue remote turn-on wire from the head unit is connected.
• Check the amplifier's gain, low-pass filter and any "sub level" setting in the head unit.
• Look for loose speaker wires at the subwoofer box terminal cup.

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