1.Confirm the wiring order. Use certified HDMI 2.1 cables. Recommended PC Setup Steps. 2.Start with EDID Mode A. Test with one display first; once stable, connect the second. 3.Set display mode: Windows: Win+P → Duplicate; match resolution/refresh • macOS: Displays → Mirror on. Why is there only picture but no sound? 1.Check the output audio mode if you do not sure the display can support which audio format.Please select the A mode, and reset the HDMI Splitter. 2.HDCP may not match very well at first connection. Please reset your HDMI Splitter by power on/off key. Can this extend to 2 different screens? No, it can not extend to 2 different screens.All splitter outputs will always have the same screens. Whether to support ARC/eARC? Soundbar need HDMI In port do not support eARC port. For advanced audio formats via ARC, use a dedicated HDMI audio extractor. About A/B Mode. When should I use A/B Mode? Duplicates HDMI video and audio from one source to two displays simultaneously; both screens show identical content (extended desktop NOT supported); suited to TVs, monitors, and projectors requiring mirrored displays. Auto Downscaling & Dual EDID Detection: Automatically detects display capabilities and adjusts resolution so each screen receives the best supported output; supports mixed display setups by scaling 8K to 4K or 1080p (720p downscaling and frame rate conversion NOT supported). Works with PS5, Xbox Series X, gaming PCs, Blu-ray players, Roku, Apple TV, Fire Stick, HDMI capture cards, amplifiers, UHD TVs, projectors, and monitors; supports HDCP 2.3. 1x UHD-1280 HDMI Splitter, 1x DC 5V USB-C Power Adapter (US Plug), 1x User Manual.