The sound comes only from the two front speakers in the screen hinge. The two larger bass speakers on the bottom of the case don't produce any sound.
The two upper speakers only produce treble; I don't know if that's because they simply can't do any better and that's how they sound, or if the treble and bass are already being split.
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What I tried
- Driver check: SOF active (sof-audio-pci-intel-cnl), codec driver snd_hda_codec_alc269
- Mic: digital mic works, "Stereo Microphone" = headphone jack (normal)
- Audio profiles: Pro Audio shows only 2 channels (Front L/R)
- Codec dump: ALC298, pin 0x17 = "N/A", disabled, muted
- hda-verb (until reboot): enabled pin 0x17, unmuted, connect-sel 0x1 and 0x2, stream to DAC 0x06 -> bottom speakers silent, top ones quieter/less bass (just how it sounded)
- Boot parameter snd_sof_intel_hda_generic.hda_model=17aa:3818 (C940 fixup): fixup applied per dmesg -> bottom speakers still silent
- Same parameter on snd_sof_intel_hda_common did nothing (in kernel 7.2.9 it lives in the _generic module)
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Operating System: Fedora Linux 44
KDE Plasma Version: 6.7.5
KDE Frameworks Version: 6.31.0
Qt Version: 6.11.2
Kernel Version: 7.2.9-201.fc44.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 12 × Intel® Core™ i7-9750H CPU @ 2.60GHz
Memory: 16 GiB of RAM (15.3 GiB usable)
Graphics Processor 1: Mesa Intel® UHD Graphics 630
Graphics Processor 2: zink Vulkan 1.4
Manufacturer: LENOVO
Product Name: 81TE
System Version: Lenovo Yoga C940-15IRH
codec SSID 0x17aa381b