Bug: snd_volume convars + soundmixer system does not work with soundentry_version 2 update_stacks

[CuteFoxModules]

Describe the bug

In 2023 Strata added a direct link between snd_volume convars (e.g. snd_volume_ui) and the soundmixer system.
This is supposed to allow direct control of mixgroup volume via convar/slider in panorama.

However this system seems to be incompatible with soundentry_version 2 update_stacks, and only works if you the default version 1 system.

If you use any update_stack , the convar stops having any effect on the volume, and the sound can be controlled via the standard soundmixer system.

Video demo here

To Reproduce

1. Open any map
2. Play any UI sound and check the effect of the UI volume slider/convar (it will work)
3. Change the UI sound's soundscript to use any update_stack, and don't change the mixgroup
4. Play the same UI sound and see that the slider/convar has no effect anymore.

Issue Map

any map

Expected Behavior

If the convars are supposed to be linked to the soundmixers directly, you would expect them to always work as long as the sound is assigned to the same mixgroup. A developer might see the convar named explicitly in soundmixers.txt and assume that the game is taking care of this and no further implementation is needed.

If developers are expected to link the convars to operator stacks themselves, there needs to be proper documentation of how the Strata addition is implemented so we can add similar behavior ourselves (e.g. feeding the convar as a variable to calculate volume in update_stacks). Otherwise the convar will have different effects on different sounds belonging to the same mixgroup.

Operating System

Windows 11, April 23 2026 build of P2CE

[TheEnderek0]

It should be noted, that this is actually what is supposed to happen. Update_stacks basically disconnect soundmixers from the playing sound.

However, what seems to actually be the bug, is that trying to read the volume level from a mixgroup linked to a convar results in that convar not being ""applied"" to that volume.

For example a simple update_stack:

	"test" {


		"mixer" { // Get the soundmixer for this sound.
			operator "get_soundmixer"
			mixgroup "Music"
		}


		"printvar1" { // Debug helper
			"operator" "util_print_float"
			"input" "@mixer.output_volume"
		}

	}

Where the Music mixgroup is linked to snd_volume_music, is always printing 1.0 (the default volume) and not the value of snd_volume_music, as it should be (without any mixlayers active).