• Please refer to the section "Error Signal" > "Blinking green light"

• Play music source which contains both left and right channel signals.

• Make sure the USB/3.5mm stereo cable is properly connected to the source.

• Adjust the Balance knob until sound is output on both speakers.

• Make sure the USB cable to computer has been disconnected when playing the AUX IN source.

• Make sure the USB/3.5mm stereo cable is properly connected.

• Make sure your computer and/or media player are not muted.

• Increase the volume on system gain control and computer.

• For Mac OS user, manually select X300A as the sound device:

1. Choose “System Preferences” from the Apple menu
2. Click “Sound”
3. Click the “Output” tab.
4. Select “KEF X300A speaker” from the device list
5. Play and enjoy your music

• For Windows XP user, increase the volume of both Windows and media player to the maximum.

• If you are using the iTunes, restart iTunes after applying new setting on the sound output.

• If you have sound control software installed in your Windows, the software may take control of the sound output selection of your computer. Select "KEF X300A Speaker" manually as your default speaker.

For Windows Vista or 7:

1. Choose “Control Panel” from the Start menu
2. Click “Sound”
3. Click the “Playback” tab
4. Check if "KEF X300A Speaker" is selected as the default speaker. If not, right click “KEF X300A Speaker” and select “Set as Default Device”

For Windows XP:

1. Choose “Control Panel” from the Start menu
2. Click “Sounds and Audio Device”
3. Click the “Audio” tab
4. Check if "KEF X300A Speaker" is selected under "Default device". If not, select "KEF X300A Speaker" as "Default device"

If the problem persists, please refer to the user's guide of your sound control software.

• Your media player may take control of the sound output selection of your computer. Please refer to the user's guide of your media player for sound output setting.

• Disconnect and connect the USB/3.5mm stereo cable again.

• Power off the speakers, then power on.

• If the problem persists, please contact your local dealer or service help desk.

• Speakers in standby mode. Check if the USB/ 3.5mm stereo cable is properly connected.

• Please refer to the section "Error Signal" > "Blinking red light"

• Make sure all power cords are plugged and the main power supply is turned on.

• Streaming online resources may result in intermitent sound output due to unstable network signal. Playing local music files in your computer is recommended.

• System sound may interrupt music playback. It is recommended to disable the system sound.

For Windows:

1. Choose “Control Panel” from the Start menu
2. Click “Sound”
3. Click the “Sounds” tab
4. Select “No Sounds” under “Sound Scheme", then click “Ok”

For Mac OS:

1. Choose “System Preferences” from the Apple menu
2. Click “Sound”
3. Click the “Sound Effects” tab
4. Uncheck “Play user interface sound effects”

• Make sure all cables are properly connected.

• Replace any damaged USB/3.5mm stereo cable.
 

• Power off the speakers and power on again after 15 minutes.

• Manually select the default sampling rate in the computer.

For Windows Vista and 7:

1. Choose “Control Panel” from the Start menu
2. Click “Sound”
3. Click the “Playback” tab
4. Double click "KEF X300A" to go to the properties page
5. Select "Advanced", select the desired sample rate uder "Default Format"

For Windows XP:

1. Choose “Control Panel” from the Start menu
2. Click “Sounds and Audio Device”
3. Click the “Audio” tab
4. Click "Advanced" under "Default device"
5. Click the "Performance" tab
6. Select "Best" for "Sample rate conversion quality"

For Mac OS X:

1. Choose "Utilities"
2. Choose "Applications"
3. Click "Audio MIDI Setup"
4. Seletct "KEF X300A"
5. Select the desired sample rate under "Format"

• Playback of files with sample rate higher than 96kHz will be down-sampled to 96kHz

There are known issues using external USB-Audio devices with Microsoft's Windows 8 operating system on some hardware platforms, which includes the KEF X300A, as well as some tablets running Windows RT. Problems include occasional and/or consistent clicks, occasional and/or consistent sound distortion and dropouts. Please stay tuned to this page for updates.