If you're suffering problems with crackling or buzzing audio from the speakers on your VIZIO HDTV, there are a number of potential troubleshooting steps you can take. Audio distortion can be caused by poorly optimised volume on satellite or cable digiboxes, SRS audio settings on your TV, or interference from an external device.
Troubleshooting audio input
Crackling or buzzing audio can result from poorly optimised volume settings. In particular, external devices such as DVD players or satellite and cable digiboxes can create audio distortion if the audio output is too low. To fix this, turn your VIZIO TV's volume all the way down to the minimum, then increase the volume on all audio sources (such as a digibox) to maximum to ensure the best quality sound reaches your TV. Then adjust the TV volume to a comfortable level.
Adjusting settings on the TV
Your VIZIO TV features built-in SRS TruVolume and TruSurround technology to provide a constant comfortable audio level and advanced surround sound. However, SRS audio adjustment can cause sound problems with some devices, so VIZIO recommend disabling both in these cases. Open the Main Menu on your TV, select Audio Settings, then select Advanced Audio. Then disable the "SRS TruVolume" setting, and repeat for the "SRS TruSurround" option.
You can also try muting the TV to see if the crackling stops.
Performing a power cycle
VIZIO recommend performing a power cycle on your TV to eliminate problems with sound crackling or humming. First, turn off your TV and unplug it from the mains. Press the power button and hold it down for 30 seconds to initiate a power cycle, then release the button. Plug the TV back into the mains, using a different socket if possible, and turn the TV back on to see if the crackling issue has been resolved.
Troubleshooting external devices
A crackling sound could be caused by a single device connected to the TV, so try disconnecting all external devices and seeing if the problem remains. If the crackling disappears, plug each external device back in one at a time to see which is causing the crackling. You can also move the TV around to see if there is any interference in the room causing the problem.
If you have any devices connected through an HDMI cable, you can try changing the audio settings on the device from "HDMI Auto" to "HDMI Fixed."