Diagnosis
Ground loop or electrical interference, often introduced via the HDMI connection, or a faulty internal amplifier.
How to Fix It
Isolate the source by changing your audio connection method.
- Disconnect the HDMI cable from the soundbar. Does the hiss stop? If yes, the issue is HDMI-related.
- Try using a digital optical cable instead of HDMI for audio. If the hiss disappears, stick with optical.
- If you must use HDMI, plug the soundbar and TV into the same power strip to ensure a common ground.
If That Didn't Work
The hiss is internal. Perform a factory reset (press and hold Bluetooth & Volume Down buttons on the soundbar for 10 seconds). If it persists, it's a hardware fault.
Heads Up
Some level of amplifier noise is normal at very close range, but it shouldn't be audible from your seating position. If it's loud, contact support.