Missing audio channels with Raspberry Pi and 5.1 Audio - General Support - LibreELEC Forum
Amazon.com: Audio HAT Module for Raspberry Pi 4B/3B+/3B/2B/B+/A+/Zero/Zero W/Pi Zero WH,WM8960 Hi-Fi Sound Card HAT Stereo CODEC, Play/Record : Electronics
Use USB Sound Card in Raspberry Pi : 5 Steps - Instructables
Raspberry Pi Audio Amplifier HIFI AMP Expansion Board for Pi 3B+ 3B 2B – Geekworm
Raspberry Pi X20 HIFI Audio Kit (X20 ES9028Q2M DAC Board,X10-PWR Power – Geekworm
Amazon.com: Geekworm Raspberry Pi Zero 2 W HiFi DAC HAT, X302 PCM5122 HiFi DAC Audio Card & 4-Port USB HUB Compatible with Raspberry Pi Zero 2 W / Zero W (Not Include
Raspberry Pi X5500 HiFi DAC+AMP Expansion Board Support X872/X710/X850 – Geekworm
Audio Injector Octo multichannel sound for the Raspberry Pi by Flatmax Studios — Kickstarter
Spatialize Monaural Audio into 5.1 Channel Surround Sound Using Raspberry Pi - MATLAB & Simulink Example
Test Sound Card and Speakers in Raspberry Pi : 10 Steps - Instructables