there's a constant hissing or static noise coming from the speakers even when nothing is playing

Diagnosis

The constant hissing or static noise you are hearing from your Samsung HW-B650 is known as "noise floor" or "amplifier hiss." This occurs when the internal amplifier is active but receiving no audio signal, causing the electronic noise inherent in the circuitry to be amplified and pushed through the drivers. In the HW-B650, this is most prevalent when using the Optical (D.IN) connection because the digital-to-analog converter (DAC) can sometimes struggle with "silent" packets of data sent by the TV, leading to a persistent white-noise floor. Additionally, this hiss is often exacerbated by a ground loop. This happens when the soundbar and the TV are plugged into different wall outlets or power strips, creating a small electrical potential difference that manifests as a 60Hz hum or a high-frequency hiss. If you notice the hiss increases in volume as you raise the soundbar's volume—even when no music is playing—you are dealing with a gain-stage issue where the amplifier is boosting the noise floor of the input signal. To confirm the source, switch the input to Bluetooth and pair a phone. If the hiss disappears, the issue is specifically related to the physical cabling or the output signal from your TV. If the hiss persists across all inputs, it is likely an internal hardware interference issue or a power supply problem.

How to Fix It

To eliminate the static and optimize the signal path, follow these precise steps:

1. Switch to HDMI ARC/eARC: The HW-B650 performs significantly better over HDMI than Optical. Unplug the Optical cable and connect a High-Speed HDMI cable from the HDMI (ARC) port on your TV to the HDMI OUT (TV-ARC) port on the soundbar. This allows for a cleaner digital handshake and better power management.
2. Adjust TV Digital Output: Using your TV remote, go to Settings > Sound > Expert Settings. Change the "Digital Output Audio Format" from 'Auto' to 'PCM'. This removes the decoding overhead from the soundbar's processor, which often reduces the audible hiss.
3. Sync Power Sources: Plug both the Samsung soundbar power adapter and the TV power cord into the same high-quality surge protector. This eliminates the ground loop potential that causes electrical interference.
4. Calibrate Volume Levels: Set your TV's internal volume to a fixed high level (around 80-90%) and use the soundbar remote to control the actual listening volume. This ensures the soundbar's amplifier isn't working overtime to boost a weak signal, which is where most hiss originates.

If That Didn't Work

• Perform a Hard Factory Reset: While the soundbar is powered on, press and hold the Volume + and Volume - buttons on the physical chassis of the unit (not the remote) simultaneously for about 5 seconds. The display will show 'INIT' and the unit will reboot. This clears any corrupted DSP settings that may be causing signal noise.
• Replace the Optical Cable: If you must use Optical, replace your current cable with a shielded Toslink cable. Cheap, unshielded cables act as antennas for EMI (electromagnetic interference) from nearby routers or power bricks.
• Isolate the Power Brick: Move the soundbar's power adapter away from other high-voltage electronics. If the power brick is sitting directly next to a Wi-Fi router or a gaming console, it can pick up electronic noise that leaks into the audio stream.
• Update Firmware: Use a USB drive to update the soundbar to the latest firmware version. Samsung frequently releases stability patches that optimize the DAC's noise floor management.

Heads Up

• Avoid using "Volume Leveling" or "Night Mode" settings on your TV, as these compress the dynamic range and can make the underlying noise floor more audible.
• Ensure the soundbar is placed at least 6 inches away from any wireless routers or microwave ovens to prevent RF interference from bleeding into the internal circuitry.
• Never use an extension cord for the soundbar's power adapter; always plug it directly into a wall outlet or a certified surge protector to maintain a clean ground.
• If you hear a "pop" followed by a hiss when the unit first turns on, this is normal capacitor charging and not a defect.