SteelSeries GameDAC does not use 24-bit audio streams
When playing audio on a SteelSeries GameDAC hardware device, the audio stream going into the hardware is always 16-bit even though it supports 24-bit audio. This can be seen on the device itself; it reports the audio stream it's currently playing.
Hardware stream info from
/proc/asound/card#/stream0 (I can report more info if needed):
SteelSeries SteelSeries GameDAC at usb-0000:00:14.0-9.2, full speed : USB Audio Playback: Status: Running Interface = 2 Altset = 1 Packet Size = 288 Momentary freq = 48000 Hz (0x30.0000) Interface 2 Altset 1 Format: S16_LE Channels: 2 Endpoint: 1 OUT (ADAPTIVE) Rates: 44100, 48000, 96000 Bits: 16 Channel map: FL FR Interface 2 Altset 2 Format: S24_3LE Channels: 2 Endpoint: 1 OUT (ADAPTIVE) Rates: 44100, 48000, 96000 Bits: 24 Channel map: FL FR Capture: Status: Stop Interface 1 Altset 1 Format: S16_LE Channels: 1 Endpoint: 1 IN (ADAPTIVE) Rates: 96000 Bits: 16 Channel map: MONO
This setup worked before in Pulseaudio by configuring it to use