DDC volume control doesn't work?

[saied-elbach]

Hello, I'm now running macOS Sonoma 14.5 on a mac mini m2 and connected to a samsung monitor model s32bm700uu via HDMI, but i am encountering a couple of issues.

1- I have a logi keyboard with sound control keys which i use to control the sound. When i use volume up or volume down the sound bar increases and decreases accordingly but the sound itself is not affected and stays the same, even when muted the sound still plays. (I tried a sound equalizer for mac to control the volume and it works, but i prefer to have one application to manage both brightness and sound).

2- The brightness control on works on the software level and it is capped at 50% brightness, if i go above the 50% it does not affect the brightness any further.

3- The brightness control doesnt work on a hardware level.

Am i doing something wrong here?
Anyway, I want to purchase the app but I want to make sure that it works first. I have been using the app for a long time now so i am through the trial period. Back then, it all looked too difficult for me to set it up properly at the beginning so i gave up on figuring it out back then but now that I have the time to do so I am trying to make some improvements.

[waydabber]

Hi there - unfortunately Samsung's Smart Monitor line generally does not support DDC. These displays are more TVs than Monitors (internally) and TVs generally don't support DDC which is required both for hardware brightness/backlight control and hardware audio control. I recommend turning DDC off for this display - this will make the entire brightness slider range available for software control.

[saied-elbach]

Thank you so much for the prompt response. You were right, when I disabled the DDC, the slider worked as intended again.
As times goes by I only regret buying this monitor more and more, even though the screen is big, the brightness is low and it doesnt play nice with mac.

[bentokill]

Hi @waydabber have the same question here concerning a LG 32GP850-B, can't find if DCC is available or not. I can control brightness and contrast but can't find a way to control volume. The slider volume does appear though but don't do anything. (Was using "background music " before, have uninstalled it since i was wondering if it could fooling around with the controls of BetterDisplay). Thx !

[waydabber]

BetterDisplay uses DDC to control volume, but not all displays support it. You can check whether this capability is available by installing betterdisplaycli https://github.com/waydabber/betterdisplaycli and running this:

betterdisplaycli get -namelike=something -ddcCapabilities

Obviously you need to replace the something with some part of your display's name. :)

If you see a line that says Default control target: volume, then the display at least reports volume control DDC capability.

Note

The ddcCapabilities command is available only in v2.3.8 (unreleased at the time of this answer) so you should download and install this pre-release first:
https://github.com/waydabber/BetterDisplay/releases/download/v2.0.0-pre-release/BetterDisplay-v2.3.8-b31277-pre.zip_

[bentokill]

Thx, i'll try that

[taoz66]

It returned Failed. What is that supposed to mean?

[waydabber]

It means that the operation did not succeed for some reason. You can also use the app's ui (the detection feature under DDC Features... for the display' settings pane).

[taoz66]

It means that the operation did not succeed for some reason. You can also use the app's ui (the detection feature under DDC Features... for the display' settings pane).

Thanks for quick replying.

The detection results in app say that the first 2 are OK but the last 2 (DDC capability report and detailed report) are unavailable. The app is able to mute and unmute my monitor, but volume control doesn't work.

What should I do to confirm whether my monitor supports volume control or not?

[waydabber]

Well, if DDC generally works but volume control does not, then it's a good indication that it is not supported. Detection may be connection type (HDMI vs DP) specific on some displays, but some don't properly support reporting DDC capabilities while DDC still works.