A dedicated solves this by sending distinct signals to each channel: Left, Center, Right, Right Surround, Left Surround, and the LFE (subwoofer).
: While primarily stereo, YouTube does support 5.1 on certain devices (like smart TVs or casting). Look for videos such as the Room Balance & Clarity Check Dolby Audio Surround Sound Test for 5.1 dolby digital 5.1 surround sound test video download
: Offers technical multi-channel AAC test files specifically for checking channel routing and phase. What to Look for in a Test Video A dedicated solves this by sending distinct signals