Lenovo 83KF with Realtek ALC287 – bass speaker not exposed (only treble on Linux, Dolby works on Windows)

[GitHub issues - opened <github@alsa-project.org>]

alsa-project/alsa-ucm-conf issue #614 was opened from Prajwal-Prathiksh:

> [!IMPORTANT]
> **I just started getting into Linux, and I'm not even sure if this is the right place to be posting this issue. I'm more than willing to learn or improve if I need to be doing something else or reaching out elsewhere :")**

### System
- Manufacturer:      LENOVO
- Product Name:      83KF
- Product Version:   Yoga Pro 7 14IAH10
- Firmware Version:  QGCN28WW
- System SKU:        LENOVO_MT_83KF_BU_idea_FM_Yoga Pro 7 14IAH10
- Board Vendor:      LENOVO
- Board Name:        LNVNB161216
- Kernel: 6.16.8-arch1-1
- Packages:
  - sof-firmware 2025.05.1-1
  - alsa-ucm-conf 1.2.14-2
  - alsa-utils 1.2.14-1
  - Audio stack: PipeWire (Arch Linux)

### Problem
- On Windows with Dolby Atmos, laptop speakers produce rich sound with bass.
- On Linux (Arch), sound is thin/treble-only. No bass speaker output.
- In `alsamixer`, only `Speaker` control is visible.
- Codec dump shows:
  - 0x14: [Fixed] Internal Speaker (plays sound, treble only)
  - 0x17/0x1b/0x1e: [N/A] Speaker at Ext Rear (do not output audio)

### What I tried
- Updated `sof-firmware` + `alsa-ucm-conf`.
- Raised mixer levels.
- Tested with `hda-verb` to enable 0x17/0x1b as output, set gain, EAPD, and connect to DAC → no sound.
- Confirmed with `speaker-test -t sine -f 80`.

### Logs
Attaching files
- [alsa-info.txt](https://github.com/user-attachments/files/22440886/alsa-info.txt)
- [amixer_contents.txt](https://github.com/user-attachments/files/22440883/amixer_contents.txt)
- [amixer_simple.txt](https://github.com/user-attachments/files/22440885/amixer_simple.txt)
- [codec_dump.txt](https://github.com/user-attachments/files/22440884/codec_dump.txt)

Issue URL     : https://github.com/alsa-project/alsa-ucm-conf/issues/614
Repository URL: https://github.com/alsa-project/alsa-ucm-conf