How do I fix audio issues with USB-C to HDMI adaptors on MacBook Air M1 and M2?

that philips tpm171e is a 4K smart TV cable of 10 bits/color (HDR) with multiple inputs

connectivity includes

2x HDMI 1.4

2x HDMI 2.0

The best you can produce with a USB-C adapter is

HDMI 1.4 up to 4K at 30 Hz when HDR is set to ON

HDMI 1.4 up to 4K at 60 Hz when HDR is set to OFF

I don't expect the HDMI 2.0 inputs to do anything when connected to an adapter.

The Mac does not rely on Windows-like side-loaded "Drivers" which are actually packages of resolutions and settings for a specific display. Instead, it goes straight to the immutable source -- it asks the display itself.

To get a Mac display to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, the display will not be shown as present, and no data will be sent to the display. "No signal detected" is generated by the DISPLAY, not by the Mac.

This query is only sent at certain times:

• at startup

• at wake from sleep — so momentarily sleeping and waking your Mac may work

• at insertion of the Mac-end of the display-cable, provided everything on that cable is ready-to-go

• hold the Option key while you click on the (Detect Display) button that will appear in Displays preferences (from another display)

so try doing some of those things and see if the display comes alive.

Modern Displays with multiple ports are sometimes busy scanning the other ports, looking for an input, and miss the query from the Mac. They need to pay attention to the port you are actually using, or they will miss the query.

Some displays have On-Screen Display settings that can be used to tell the display a computer is attached on a certain port, or a certain port should be highest priority. Changing those may make your display more responsive.

Some displays include their own private "sleep" settings for the display alone. This can allow the display to enter its own sleep mode, on top of the Mac's not sending it data. A display that is sleeping on its own can generally not respond to the Mac's query, and will stay dark.

I recommend you turn OFF mirroring.

Mirroring calculates a compromise resolution that appears to eb attainable by BOTH displays. then it runs Both display in lock step at exactly the same refresh rate.

It is possible it is also sending audio to "both" displays be sending audio only to the Internal display and speaker.

Since the issue is an audio issue, you may need to open the Audio MIDI Setup (Applications->Utilities). You may need to tweak the type of audio being sent to the display. You may need to try different settings there until you find one that works. I have found sometimes when connecting to TVs, it is not as straight forward as connecting to a dedicated computer display. Also, sometimes there is not a one setting fits all solution depending on the setup.

Using a generic no-name USB-C/Thunderbolt to HDMI adaptor, I was able to mirror YouTube official music videos to a TV, with just the specific System Settings for Displays and Sound. Mirroring or Extended Display (2nd screen) both work just fine for this.

For YouTube, HDCP-compliancy may not even be necessary, as (most of) the content wouldn’t be capture-protected per se. Though there could be other interesting content from other sources and/​or Mac apps that does require HDCP-compliancy (e.g. TV app), so shopping for a compliant adaptor is advised.

what make&model displays are you connecting?

that samsung ue22h5005ak appears to be a 1920 by 1080 TV

connectivity includes

2x HDMI 1.4