diff --git a/session-logs/2026-03-20-session.md b/session-logs/2026-03-20-session.md
index 60e1fe8..5eeb12d 100644
--- a/session-logs/2026-03-20-session.md
+++ b/session-logs/2026-03-20-session.md
@@ -638,3 +638,224 @@ Tested GrepAI with three semantic searches — all returned relevant results wit
 3. **GrepAI re-index** — After major file moves, GrepAI watcher should pick up changes automatically, but verify with `grepai status`
 4. **Remaining root docs** — Could further organize CATALOG_*.md, CREDENTIAL_*.md, etc. if desired
 5. **scripts/README.md** — May need update since many scripts moved out
+
+---
+
+## Update: 19:30 — Lenovo Legion Pro 7 Sound Quality Fix (CachyOS/Linux)
+
+### Session Summary
+
+Diagnosed and partially fixed terrible speaker sound quality on Lenovo Legion Pro 7 16IAX10H (acg-guru-5070) running CachyOS Linux. Root cause: kernel using legacy HDA driver instead of Intel SOF (Sound Open Firmware), leaving the Awinic AW88399 smart amplifier speakers running without DSP processing. On Windows, Dolby Atmos / Nahimic provides this processing. Created modprobe config to force SOF driver, rebuilt initramfs — pending reboot to test.
+
+### Hardware Details
+
+- **Laptop:** Lenovo Legion Pro 7 16IAX10H (ASUS, DMI product: 83F5)
+- **Audio Controller:** Intel Corporation 800 Series ACE (Audio Context Engine) rev 10
+  - PCI: `80:1f.3`
+  - PCI Subsystem: Lenovo `3d6c`
+- **Audio Codec:** Realtek ALC287
+  - Codec Subsystem ID: `0x17aa3906`
+  - Outputs: 0x14 (Speaker), 0x17 (Bass Speaker), 0x21 (Headphone)
+  - Inputs: 0x12 (Internal Mic), 0x19 (External Mic)
+- **Smart Amplifier:** Awinic AW88399 (kernel module `snd_soc_aw88399` loaded but NOT active)
+  - Library module: `snd_soc_aw88395_lib`
+  - These are DSP-driven speakers designed to be tuned by firmware — running "raw" without DSP sounds flat/terrible
+- **NVIDIA Audio:** GB205 High Definition Audio Controller (HDMI audio, card 0)
+- **Webcam:** Integrated Camera (V4L2)
+
+### Problem Statement
+
+Sound quality on built-in speakers is significantly worse on Linux compared to Windows. Thin, flat, no bass, lacking clarity. On Windows, Dolby Atmos / Nahimic / Lenovo Vantage provides DSP processing through the AW88399 smart amp firmware. On Linux, none of this exists.
+
+### Diagnosis — Step by Step
+
+#### 1. PipeWire/EasyEffects Configuration (from lost previous session)
+
+EasyEffects 8.1.6 was already installed (from a previous session that was lost due to unsaved `/save` before reboot). Previous session had:
+- Installed EasyEffects: `pacman -S --noconfirm easyeffects` (snapshot 40, 18:35:09)
+- Installed LV2 plugins: `pacman -S --noconfirm lsp-plugins-lv2 calf zam-plugins-lv2 mda.lv2` (snapshot 42-43, 18:35:21-24)
+- Created "Legion-Speakers" preset with bass enhancer, 10-band EQ, loudness, limiter
+- Configured autostart: `~/.config/autostart/com.github.wwmm.easyeffects.desktop`
+
+#### 2. Audio Routing Was Broken
+
+**Finding:** EasyEffects was running (PID 34011) and its virtual sink existed (node 68), but audio was NOT routing through it.
+
+```
+Default Sink: 800 Series ACE (Audio Context Engine) Analog Stereo (node 50)  ← WRONG
+Easy Effects Sink: node 68  ← existed but unused
+```
+
+All apps were sending audio directly to hardware, completely bypassing EasyEffects.
+
+**Fix:** `wpctl set-default 68` — set EasyEffects Sink as default output.
+
+**Persistence:** WirePlumber automatically saved to `~/.local/state/wireplumber/default-nodes`:
+```
+[default-nodes]
+default.configured.audio.sink=easyeffects_sink
+```
+
+#### 3. EasyEffects Preset Was Too Conservative
+
+Original "Legion-Speakers" preset:
+- Boosted 30Hz (+6dB), 60Hz (+5dB) — **completely wasted** since laptop speakers can't reproduce anything below ~150-200Hz
+- Modest boosts at 120Hz (+3), 250Hz (+1), 8kHz (+2), 16kHz (+3)
+- Loudness compensation at -14dB
+- Limiter at -1dB threshold
+
+**Created "Legion-Speakers-v2" preset** at `~/.local/share/easyeffects/output/Legion-Speakers-v2.json` with:
+- **High-pass filter at 60Hz** (x2 slope) — stops wasting energy on inaudible frequencies
+- **15-band EQ** targeting frequencies the speakers CAN reproduce:
+  - 150Hz +4dB, 250Hz +6dB, 400Hz +3dB (perceived bass/warmth)
+  - 800Hz -1dB (reduce boxiness)
+  - 1.5kHz +2dB, 3.5kHz +3dB, 5kHz +4dB, 7kHz +3dB (clarity/presence)
+  - 10kHz +5dB, 14kHz +4dB hi-shelf (air/sparkle)
+  - 2.5kHz -2dB narrow Q (reduce harshness/tinny quality)
+- **Bass Enhancer:** amount=12, floor=120Hz, scope=200Hz (generates harmonics that speakers CAN play)
+- **Exciter:** amount=6, scope=4kHz (high frequency harmonic generation)
+- **Crossfeed:** fcut=700, feed=4.5 (subtle stereo blending for closely-spaced laptop speakers)
+- **Loudness compensation:** ISO226:2003, volume=-20dB (more aggressive)
+- **4-band multiband compressor:**
+  - Band 0 (<250Hz): ratio 3:1, threshold -16dB, makeup +4dB
+  - Band 1 (250-1500Hz): ratio 2.5:1, threshold -14dB, makeup +2dB
+  - Band 2 (1.5-5kHz): ratio 2:1, threshold -12dB, makeup +3dB
+  - Band 3 (5kHz+): ratio 2:1, threshold -12dB, makeup +4dB
+  - Output gain: +6dB
+- **Limiter:** ALR enabled, x2 oversampling, threshold -1dB
+
+**User reported only "slight" difference** — confirmed EasyEffects alone can't compensate for missing DSP firmware.
+
+#### 4. Root Cause: Wrong Audio Driver
+
+**Critical finding:** The kernel was using `snd_hda_intel` (legacy HDA driver) instead of `snd_sof_pci_intel_mtl` (Sound Open Firmware).
+
+Evidence:
+```
+# Driver in use
+/sys/bus/pci/devices/0000:80:1f.3/driver -> snd_hda_intel
+
+# DSP driver selection: 0 = auto, chose legacy
+/sys/module/snd_intel_dspcfg/parameters/dsp_driver = 0
+
+# Both modules available
+Kernel modules: snd_sof_pci_intel_mtl, snd_hda_intel
+```
+
+**Why this matters:**
+- Without SOF, the Intel ACE DSP hardware sits idle
+- The AW88399 smart amplifier module is loaded (`snd_soc_aw88399`) but NOT active — zero kernel messages about it
+- The ALC287 codec picked a generic fallback fixup: `picked fixup for PCI SSID 17aa:0000` (should be `17aa:3906`)
+- The speakers run in "dumb" analog mode without any DSP tuning
+
+#### 5. SOF Firmware Status
+
+- **Package:** `sof-firmware 2025.12.2-1` — already installed
+- **Firmware files available:**
+  - `/lib/firmware/intel/sof-ipc4/arl/sof-arl.ri` (Arrow Lake)
+  - `/lib/firmware/intel/sof-ipc4/arl-s/sof-arl-s.ri` (Arrow Lake-S)
+  - HDA-generic topologies: `sof-hda-generic-ace1-*.tplg` (ACE1 = Arrow Lake)
+- **AW88399 topology:** No specific AW88399 topology file found — may use generic HDA topology
+
+### Fix Applied (Pending Reboot)
+
+#### Force SOF Driver
+
+Created `/etc/modprobe.d/sof-force.conf`:
+```
+options snd_intel_dspcfg dsp_driver=3
+```
+
+Parameter values: 0=auto, 1=legacy, 2=SST, 3=SOF, 4=AVS
+
+#### Rebuilt Initramfs
+
+```bash
+sudo mkinitcpio -P
+```
+
+Both kernels rebuilt:
+- `linux-cachyos` (6.19.9-1-cachyos)
+- `linux-cachyos-lts` (6.18.19-1-cachyos-lts)
+
+Limine boot entries updated automatically.
+
+#### Rollback Plan
+
+If SOF driver breaks audio after reboot:
+1. Boot into LTS kernel from Limine menu
+2. Or boot a btrfs snapshot (8 snapshots available in Limine)
+3. Remove the config: `sudo rm /etc/modprobe.d/sof-force.conf && sudo mkinitcpio -P`
+
+### ALSA Mixer State (Reference)
+
+All levels verified at maximum before EasyEffects testing:
+```
+Master Playback Volume: 87/87 (0dB)
+Speaker Playback Volume: 87/87 (0dB) — unmuted
+Bass Speaker Playback Switch: on,on
+PCM Playback Volume: 255/255 (0dB)
+```
+
+### Audio Pipeline (Current — PipeWire)
+
+```
+Server: PipeWire 1.6.2 (PulseAudio compat 15.0.0)
+Sample: float32le 2ch 48000Hz
+
+Devices:
+  Card 0: HDA NVidia (GB205, HDMI audio)
+  Card 1: HDA Intel PCH (800 Series ACE, ALC287)
+
+Sinks:
+  50: 800 Series ACE Analog Stereo (hardware)
+  68: Easy Effects Sink (virtual, set as default)
+
+Audio chain: App → EasyEffects Sink (68) → bass_enhancer → exciter → equalizer →
+             crossfeed → loudness → multiband_compressor → limiter → Hardware (50)
+```
+
+### Key Technical Details for Forum Post
+
+1. **Laptop:** Lenovo Legion Pro 7 16IAX10H (DMI: 83F5)
+2. **Audio hardware:** Intel 800 Series ACE + Realtek ALC287 + Awinic AW88399 smart amp
+3. **OS:** CachyOS (Arch-based), kernel 6.19.9-1-cachyos
+4. **Bootloader:** Limine 10.8.5
+5. **Problem:** `snd_intel_dspcfg` auto-detection (dsp_driver=0) selects legacy `snd_hda_intel` instead of `snd_sof_pci_intel_mtl`
+6. **AW88399 driver loaded but inactive** — no DSP processing for smart amp speakers
+7. **ALC287 fixup wrong:** Kernel matches `17aa:0000` (generic) instead of proper SSID `17aa:3906`
+8. **Fix:** Force SOF via modprobe: `options snd_intel_dspcfg dsp_driver=3`
+9. **EasyEffects** can partially compensate but cannot replace hardware DSP processing
+10. **SOF firmware package:** `sof-firmware 2025.12.2-1` has ARL firmware and ACE1 topologies
+
+### Files Created/Modified
+
+- `/etc/modprobe.d/sof-force.conf` — force SOF driver (created)
+- `/home/guru/.local/share/easyeffects/output/Legion-Speakers-v2.json` — aggressive EQ preset (created)
+- `/home/guru/.local/state/wireplumber/default-nodes` — default sink set to easyeffects_sink (modified by wpctl)
+- `/boot/*/initramfs-linux-cachyos` — rebuilt with SOF config
+- `/boot/*/initramfs-linux-cachyos-lts` — rebuilt with SOF config
+- `/boot/limine.conf` — updated by mkinitcpio (auto)
+
+### Packages Already Installed (from lost session)
+
+- `easyeffects` 8.1.6-1.1
+- `lsp-plugins-lv2` (LV2 audio plugins)
+- `calf` (Calf Studio Gear audio plugins)
+- `zam-plugins-lv2` (ZamAudio LV2 plugins)
+- `mda.lv2` (MDA LV2 plugins)
+- `sof-firmware` 2025.12.2-1 (was already installed)
+
+### Pending/Incomplete
+
+1. **REBOOT REQUIRED** — SOF driver change won't take effect until reboot
+2. **Post-reboot verification:**
+   - Check `cat /sys/module/snd_intel_dspcfg/parameters/dsp_driver` = 3
+   - Check `lspci -v -s 80:1f.3` shows `Kernel driver in use: snd_sof_pci_intel_mtl`
+   - Check `journalctl -k | grep -i "sof\|aw88"` for firmware loading
+   - Check `wpctl status` for new device names
+   - Test actual sound quality
+3. **If SOF works but AW88399 still inactive** — may need Option B: load amp calibration data, check for missing topology
+4. **If SOF breaks audio** — rollback via snapshot or remove `/etc/modprobe.d/sof-force.conf`
+5. **Forum post** — document full fix once verified working, post to community.azcomputerguru.com
+6. **EasyEffects may need reconfiguration** after SOF switch — device names/IDs will change