When you change EDID, Apple TV 4K can behave differently from a generic source because it remembers successful EDID states. The manual says that selecting a new EDID can cause Apple TV 4K to ask to retest Dolby Vision and/or HDR. Once that same EDID has been tested successfully, selecting it again may not trigger the same test.
Why Dolby Vision may retest after an EDID change
From the source's perspective, a new EDID can look like a different display capability set. That is exactly what DR HDMI 8K is designed to control, so a retest is expected behaviour when you deliberately change the advertised EDID.
Atmos detection note
The manual's Apple TV 4K FAQ says to make sure the Apple TV audio setting “Change Format” is turned off when trying to allow Atmos detection through the DR HDMI 8K capability path. If Change Format had previously been enabled to force Dolby Digital 5.1, leaving it enabled can prevent the expected format detection.
Netflix 5.1 vs Atmos note
The manual also notes that an app interface may initially show 5.1 even when the source is capable of Atmos, and separately suggests checking Netflix account playback quality if Atmos works in other apps but Netflix remains limited.
A clean Apple TV EDID test
- Select the EDID you want to test.
- Allow Apple TV to complete any Dolby Vision/HDR test it requests.
- Confirm the DR HDMI 8K RX/TX state and the active EDID.
- Check Apple TV audio settings before concluding that the HDMI chain is limiting Atmos.
- Retest the same EDID only after the first negotiation has completed.
Frequently asked questions
Why does Apple TV 4K ask to test Dolby Vision again?
The manual says Apple TV remembers successful EDIDs. A new EDID can trigger a new Dolby Vision or HDR test.
What Apple TV audio setting does the manual mention for Atmos?
The manual says Apple TV 4K “Change Format” should be turned off so the source can detect Atmos capability.
Can DR HDMI 8K present different EDIDs to Apple TV 4K?
Yes. You can select predefined or custom EDIDs, or use a modified sink EDID.
Need the hardware?
Open the DR HDMI 8K product page on HDfury.uk.