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KEF Subwoofer Not Working

White subwoofer on the floor

KEF make stand alone subwoofers that can be connected to a speaker system or to a home theater system. In some cases, it won’t work at all out of the box, or it will suddenly stop working. Today, I will explain what to do if your KEF subwoofer is not working.

As a general rule, begin by checking that your KEF subwoofer is getting power. This is done by plugging a different device into the same wall outlet. If it is getting power then make sure it’s switched on. If the light comes on, then do the following steps below.

Double check the signal cables are all plugged in correctly with the help of your owners manual. And if it’s still not working, then KEF recommends contacting KEF support to have your subwoofer repaired or replaced. There are more specific issues that can occur with your KEF subwoofer so below I will provide step by step instructions for how to fix these.

KEF Subwoofer Not Working

A KEF subwoofer can be turned on but not playing any sound. Or, it can not turn on at all. Below is how to troubleshoot a KEF subwoofer that is not working.

In general, first check that your subwoofer is getting power from the wall outlet. If the light on your subwoofer is red it indicates it’s getting no audio signal, so there is an issue with the way it’s connected to the audio source. If these are both fine, do the steps below.

The wall outlet can be tested by plugging in something else. Typically a phone charger is the easiest. If the wall outlet isn’t supplying power then check the switchboard in your home.

The circuit breaker to the part of the house where the wall outlet can have tripped or blown, and needs to be switched back on or replaced. If it’s getting power, when your KEF subwoofer is plugged in a light will show on your subwoofer.

Blue means it’s on, red means it’s in standby mode, and no light means it’s not turned on. Refer to your owners manual to make sure the audio cables are all connected correctly.

KEF Subwoofer Keeps Turning Off

Black subwoofer on the floor

While a KEF subwoofer is playing it can suddenly turn off. Or, while your KEF subwoofer is sitting idle it can turn off. This is what to do when this happens.

As a general rule, a KEF subwoofer will go into standby mode if it’s not getting any audio signal. Otherwise, the wall outlet can not be providing enough power because too many devices/appliances are plugged into the same wall outlet. If it’s neither of these issues, contact KEF support.

A KEF subwoofer can be set to manual or auto. On manual it will never turn off and the light will always be blue. If it’s on auto, the light will be blue when it’s playing audio.

But, when it’s not, it will go into standby mode and the light will turn red. This is normal operation and you don’t need to do anything. If it shuts off and the light goes completely off while it’s playing or when it’s sitting idle the issue is either with the wall outlet or the subwoofer itself.

This article and its contents are owned by Ready To DIY and was first published on 07/16/2022.

Your subwoofer may be trying to draw power but the wall outlet can’t supply enough because too many devices are plugged in, in close proximity to the wall outlet your subwoofer is using. To isolate if it’s the wall outlet, unplug all other devices that are close to your subwoofer, and see if the issue persists. If it does, the issue is not with the wall outlet, and is with your subwoofer. In this case, contact KEF support.

KEF Subwoofer Red Light

White subwoofer on the floor

A KEF subwoofer has a handy light that shows exactly what status your subwoofer is in. Each of the different light colors indicates something different. Here’s what it means if the light on your KEF subwoofer is red.

A red light indicates your KEF subwoofer is in standby mode. This occurs if your KEF subwoofer is set to Auto mode. It will switch to standby mode when there is no audio signal, then turn on and begin producing sound when it receives an audio signal. How to change the mode is explained below.

There is a switch at the rear of your KEF subwoofer that is labeled Auto and Manual. It can be changed from auto to manual using this switch.

Auto is the best because it will conserve electricity. But, setting it to manual is helpful if you’re trying to troubleshoot the audio on your KEF subwoofer.

KEF Subwoofer No Sound

Black subwoofer on the floor

It’s good news when your KEF subwoofer is getting power and light is either blue or red indicating that it’s turned on. While it’s turned on but not producing any sound there are a few things to check. Below is what these are and how to fix a KEF subwoofer that has no sound.

In general, your KEF subwoofer is not receiving an audio signal. It can be caused by the audio cables being connected incorrectly. But, first check that your KEF subwoofer is turned on by seeing whether the colored light is on. After that do the following steps.

The colored light should be either red or blue, which indicates your KEF subwoofer is getting power. If it’s not getting power, refer to the section below that is titled ‘KEF Subwoofer No Power’. Otherwise there are 4 potential issues that can be causing no sound output from your KEF subwoofer.

  1. The master volume on your receiver is too low, or the device you’re using to send an audio signal like a smartphone
  2. The bass level on your receiver, or the device you’re using to send an audio signal is set too low
  3. The volume on your subwoofer is set too low
  4. The cables are installed incorrectly
  5. The cables are faulty

It can be a good idea to test the audio using a smartphone and an RCA cable. This can isolate if the issue is with the audio source. If a smartphone plays audio but your receiver or TV doesn’t then you can be sure it’s how the wires are set up.

Or, one of the cables is faulty. If none of these steps got the sound to begin working then contact KEF support.

This article and its contents are owned by Ready To DIY and was first published on 07/16/2022.

KEF Subwoofer No Power

White subwoofer on the floor

The light on your KEF subwoofer is used to determine if your KEF subwoofer is switched on and receiving power. No light indicates it’s switched off or there’s no power from the wall outlet, a red light indicates it’s in standby mode, and if the light is blue it means it’s turned on and can play an audio output. If you’re getting no power to your KEF subwoofer here’s what you should do.

Overall, the wall outlet is not supplying power, or your KEF subwoofer has an internal fault. Check the wall outlet is supplying power by plugging a different device into the same wall outlet. Then, check that it’s turned on by looking at the power switch at the back. After that, do the following.

If it is turned on, and the wall outlet is supplying power, then there is an internal issue with your KEF subwoofer. When this is the case, you should contact KEF customer support to see if the repair is covered under warranty and to organize having it repaired or replaced.

KEF Subwoofer Buzzing Noise

White subwoofer on the floor

Speakers like subwoofers can often have a buzzing noise or hum. This is generally very easy to troubleshoot but there are a few potential things that can be causing it. Here’s what to do if your KEF subwoofer is making a buzzing noise.

As a general rule, this is caused by a ground loop. To identify if it’s a ground loop disconnect all cables from your KEF subwoofer except for the power cable. Then turn your KEF subwoofer on and turn the volume up to the max. If there is no buzzing noise then it’s a ground loop.

A ground loop is very common. There are a range of ways to fix it.

If a ground loop is not the issue, then you should contact KEF support.

How to Hard Reset KEF Subwoofer to Factory Settings

Black subwoofer on the floor

A hard reset is a good way to revert any settings, and solve issues with electronics such as a subwoofer. There is no hard reset button visible on a KEF subwoofer. So, here’s how to hard reset a KEF subwoofer.

There is a button inside a small pinhole opening that is labeled with a triangle on the back of your subwoofer close to where all of the audio cables are plugged in. However, only a few KEF subwoofers have this factory reset button. All others can not be hard reset.

This article and its contents are owned by Ready To DIY and was first published on 07/16/2022.

To identify if your KEF subwoofer has a hard reset button refer to the owner’s manual for your specific KEF subwoofer model. I’ve looked through most of the KEF subwoofer manuals, and only a few have this button.

Therefore, as a general rule, a KEF subwoofer can not be hard reset. A soft reset can be performed by turning it off, disconnecting it from the power, waiting for 30 seconds, then plugging it back in again and turning it back on.

Overall, start by isolating whether it’s a power supply issue, a wiring issue, or an issue with an internal component on your KEF subwoofer. Check the wall outlet is supplying power by plugging another device into the same wall outlet. Then, do the steps above.