HDMI Audio Troubleshooting – Quick Guide

This guide helps diagnose, test and troubleshoot common HDMI audio issues with simple HDMI switchers, matrix switchers, and other HDMI AV equipment. If you have BZBGEAR equipment and still need assistance after following this guide, please email support@bzbgear.com. 

1. Confirm Audio Compatibility (Most Common Cause)

Every device in the signal chain must support the selected audio format. Essentially, you’ll have to either check product manuals, do a quick browser search, or go into the settings of each device to see if the audio format being used on one device is an option for all. 

• Source (PC, console, media player)
• HDMI device (switcher, matrix, extender)
• Audio endpoint (TV, AVR, soundbar)

If any device does not support the active format, audio may drop out or stop entirely.

2. Test with Basic Audio Formats First

Start with formats supported by almost all HDMI devices:

• Set source audio to LPCM 2.0 or Dolby Digital (5.1)
• Confirm audio is stable
• Switch inputs multiple times (if applicable)
• Power-cycle all devices and retest

If basic formats work but advanced formats fail, the issue is almost always EDID or channel mismatch.

3. Match EDID to Audio Channel Requirements

HDMI audio is negotiated via EDID. Channel count matters.

Common issue example:

• Source: Dolby Digital 5.1
• EDID: 2.0CH
• Result: No audio, or some audio issues

Correct EDID selection:

• 2.0CH > Stereo PCM only
• 5.1CH > Dolby Digital, DTS, DD+
• 7.1CH > TrueHD, DTS-HD, Atmos, DTS:X

Avoid “Auto EDID” while troubleshooting; manual selection is more reliable when narrowing down what works best for the system. Basically, you want to see which formats in particular are working and which ones are having problems. 

4. Always Match the Weakest Device

When multiple displays or audio devices are connected, EDID should match the least capable device unless audio downmixing or extraction is used.

Examples:

• TV stereo only > 2.0CH EDID
• Soundbar (Dolby Digital) > 5.1CH EDID
• AVR with Atmos > 7.1CH / Atmos EDID

Using an EDID beyond a device’s capability can cause:

• No audio
• Dropouts
• Audio switching back to TV speakers

5. Check HDMI-CEC / ARC / eARC (If Used)

CEC and ARC/eARC can override manual audio routing.

Quick test:

1. Temporarily disable CEC, ARC, and eARC
2. Test audio stability
3. Re-enable features one at a time if needed

HDMI Audio Format Matching Cheat Sheet