Your music. Your curve. Your workspace.
A Windows parametric EQ editor for FiiO and Snowsky devices, and for any Windows output through Equalizer APO.
Download • Changelog • Discord app channel • Report an issue
No FiiO DAC? No problem. Software EQ brings WolfEQ's headphone library, AutoEQ search, and curve editor to any Windows output: laptop jacks, USB dongles, other brands' DACs, and Bluetooth headphones. WolfEQ drives Equalizer APO for you, so edits play live without touching a config file. FiiO and Snowsky support works exactly as before.
| New in 0.8.0 | |
|---|---|
| 🖥️ Software EQ | Pick it in the device list, choose your outputs, and hear every edit within a moment. |
| 📦 Equalizer APO included | The official installer ships with WolfEQ; one button starts setup. |
| ⏯️ Bypass anywhere | Compare EQ on and off from the app or the tray, without losing your curve. |
| 🤝 Plays well with Peace | WolfEQ keeps to its own file and one marked line, and warns about stacked EQ. |
| ⌨️ Automation | --system-eq-bypass and --preset for Stream Deck and scripts. |
| 📚 A roomier library | List and large preview side by side, Favorites, rename, and one-click saving from online results. |
| 🔀 Quicker switching | A device menu in the toolbar, a clearer USER slot menu, and color-coded connection status. |
| 📌 A new tray | Now playing, an EQ switch, and quick presets in Software EQ mode. |
Still here from 0.7.0: the redesigned workspace, colorful live spectrum bars, light and dark backgrounds, and a faster path from finding a preset to making it yours.
App render with an illustrative spectrum. Band controls start collapsed; expand them when you want hands-on faders or a table.
| Workspace highlights | |
|---|---|
| 🎚️ Make room for your mix | Drag EQ nodes, edit frequency/gain/Q/filter shape, and resize Band controls live with the divider. |
| 🎶 See what's playing | Colorful spectrum bars behind the curve, with smooth motion and a one-click toggle. |
| 🎨 Make it yours | Light or dark backgrounds, green by default, solid accents, and Aurora, Sunset, Neon, and Ocean palettes. |
| 📚 Find, name, and open | A compact library, naming before saving, Curve/Table online previews, and local names for device slots. |
| ⌨️ One-button switching | A Windows ScriptDeck setup flyout generates a ready-to-paste PowerShell command for your saved device. |
| ✨ Details that connect | Theme-aware icons, device thumbnails, selected-band highlights, subtle glows, and a larger transparent app/tray logo. |
See light mode
Choose Settings → Appearance → Background. Background mode is saved, and accent colors adapt for readable contrast.
- Windows x64 installer — normal installation and shortcuts.
- Portable Windows x64 ZIP — extract everything, then run
WolfEQ.exe. - Both include the .NET runtime and the official Equalizer APO 1.4.2 x64 installer for Software EQ. SHA-256 checksums are supplied with the release.
Using a FiiO or Snowsky device? Follow the steps below. Using anything else, such as a laptop jack, another DAC, or Bluetooth headphones? Start with Software EQ.
- Connect your DAC over USB. In Settings → Device → Connections, refresh the list, select your device, and save the connection.
- For supported K13 lighting controls, select its Bluetooth connection too. Use Identify to confirm you have the same unit.
- Open Library. Choose a saved preset, or search AutoEQ and OPRA on the Discover online tab and check its Curve or Bands preview.
- Choose Open in editor. Opening a preset closes the library; browsing alone does not replace your edits.
- Shape the curve or expand Band controls. Use Optimize headroom to make room for boosts, then Save to Library to choose a name.
- Select the intended USER slot and write when ready. On supported devices, Live sync sends edits automatically; its question-mark tooltip explains the behavior.
The Tools menu groups editing, A/B comparison, device preparation, and sharing. Undo/redo is available in the title bar and with Ctrl+Z / Ctrl+Y. Import and Export at the top of the library cover Equalizer APO / Peace, FiiO XML, WolfEQ JSON, and library backups.
Software EQ applies WolfEQ's EQ to any Windows playback output you choose, using Equalizer APO as the audio engine. The library, AutoEQ and OPRA search, graph, band controls, undo/redo, and presets all work the same as with a DAC. There are no USER slots to write: edits reach your outputs within about a quarter of a second, and the EQ keeps playing after WolfEQ closes.
Setup
- Choose Software EQ from the device menu in the toolbar (or Settings → Device). WolfEQ remembers this choice.
- If Equalizer APO is not installed, choose Install Equalizer APO. WolfEQ uses the official Equalizer APO 1.4.2 installer it ships with (or downloads and verifies it if missing) and shows progress. Windows asks for administrator permission.
- In Equalizer APO's Device Selector, tick each output you want to EQ (for example Speakers or Headphones) and close it.
- Restart Windows if the installer asks you to.
- Back in WolfEQ, tick the same outputs in the Software EQ output list. Each output shows whether Equalizer APO is active on it. Use Add outputs to reopen the Device Selector later.
Nothing is applied until at least one output is ticked.
Bypass. Turn the EQ off and on from the editor or the tray without losing your curve. Bypass is remembered across restarts. Choosing a FiiO device again turns Software EQ off; Remove from Equalizer APO (or uninstalling WolfEQ) takes WolfEQ's EQ out of Equalizer APO completely.
Coexistence with Peace and hand-written configs. WolfEQ keeps its EQ in its own WolfEQ.txt file and adds one marked block to Equalizer APO's config.txt. The rest of config.txt is left alone, and WolfEQ restores its block if another tool rewrites the file. If Peace is also active, or a ticked output is a FiiO device that may already have EQ on board, WolfEQ shows a double-EQ warning. It does not block you; turn one of them off if the sound is doubled.
Limitations
- Apps that use exclusive mode (WASAPI exclusive) or ASIO bypass Equalizer APO, so they play without Software EQ. There is no workaround.
- Windows feature updates and audio driver updates can remove Equalizer APO from an output. If an output's status changes, use Add outputs, tick it again, and restart if asked.
- Bluetooth headphones appear as two outputs: stereo and hands-free (used during calls). Tick each one you want to EQ.
- Software EQ uses the editor's 10-band limit and applies the same EQ to both channels.
The Spectrum toggle beside EQ Curve shows audio playing through the default Windows multimedia output. It is a visual monitor: it does not process audio or measure the DAC's final analog response. Spectrum height uses its own relative level scale, separate from the EQ gain axis.
- Enabled by default; an explicitly saved off choice is respected.
- Follows output-device changes and fades to silence when playback stops.
- Pauses capture and animation when disabled, hidden, minimized, inactive, or scrolled out of view.
- Separate drawing layers, cached colors, and precomputed FFT data reduce repeated work.
Open Library for your presets on the left and a large preview on the right: the curve or a band table, preamp, filter count, whether the preset fits your device, and where it came from.
- My Library, Favorites, and Discover online tabs. Saved presets can be filtered by category; online results by AutoEQ or OPRA.
- Hover a saved preset to star it, rename it (✎ or F2), or delete it. Double-click opens it in the editor.
- Hover an online result to save it to My Library without opening it.
- Import and Export sit at the top of the library: Equalizer APO / Peace text, FiiO XML, WolfEQ JSON, library backups, and a copyable tuning report.
- Save to Library asks for a name before saving. Online presets are saved locally before opening or writing.
WolfEQ remembers descriptive names locally for each saved USB device and slot. They appear in the USER slot menu, the tray, and the selected-slot subtitle. These labels stay on your PC; they are not names written into device firmware.
Click or right-click the green waveform for the tray panel. Double-click it or choose Open editor to return to the workspace.
- Now playing shows the active slot or preset. In Software EQ mode it has an EQ switch for bypass.
- FiiO mode shows your USER slots as chips, with a check on the active one. Software EQ mode shows up to six quick presets, favorites first.
- Tray options holds Close to tray (on by default) and Minimize to tray (off by default). Both are saved.
- Quit exits the app and checks for unsaved edits.
Tray and automation switches select EQ already stored on the device. Save or discard editor changes before switching; use the editor to write a library preset into a slot.
In Settings → Integrations, open Windows ScriptDeck setup:
- Follow the link to Windows ScriptDeck by Start-Automating in the Elgato Marketplace.
- Choose the USER slot to switch to.
- Copy the generated PowerShell script. WolfEQ fills in its executable location and saved USB device path, with argument quoting handled for you.
- Add the plugin's script action to a Stream Deck key and paste the script into On Press. Repeat for other slots.
Re-copy scripts if you move WolfEQ or change its saved connection. For lighting, save the Bluetooth connection and enable Apply saved lighting when switching USER slots under Profile Lights.
The existing Save shortcut workflow is also available: assign the exported .lnk to Stream Deck's System → Open action.
Command-line automation and exit codes
WolfEQ.exe --slot 2
WolfEQ.exe --device "Desk K13" --slot 3
WolfEQ.exe --list-devices
WolfEQ.exe --help
WolfEQ.exe --system-eq-bypass toggle
WolfEQ.exe --preset "My Headphones"
In Software EQ mode, --system-eq-bypass on|off|toggle controls bypass and --preset "<name>" loads a library preset by name and applies it to your chosen outputs. --slot is not available in Software EQ mode and returns a clear "not available in Software EQ mode" result. An unknown preset name returns an error.
--device accepts the saved connection name or exact USB path. It must match the saved connection and never silently reassigns Bluetooth. Existing instances receive requests without taking focus; cold commands run without opening the editor.
Exit codes: 0 success, 1 failure/disconnected, 2 invalid arguments/unsupported slot, 3 busy/unsaved edits, 4 slot switched but lighting failed.
Results are also written to %LOCALAPPDATA%\WolfEQ\automation-result.json. Use PowerShell Start-Process -Wait -PassThru when you need the GUI executable's exit code.
| Device | Status | Notes |
|---|---|---|
| Software EQ | 🆕 Beta | Any Windows playback output through Equalizer APO 1.4.2 (bundled installer). Live edits, bypass, 10-band PEQ, no USER slots. See Software EQ. |
| FiiO K13 R2R | ✅ WolfEQ verified | Main tested target. USB detection, EQ readback, USER slot switching, PEQ writes, global preamp writes, preset storage, LED cues, USB/COAX input switching. |
| FiiO BR15 R2R | Community-sourced 10-band layout and USER 1-10 save path. Save-only until WolfEQ readback is physically verified. | |
| FiiO QX13 | Community-sourced 10-band layout and USER 1-10 save path. Save-only until WolfEQ readback is physically verified. | |
| FiiO BTR17 | Community-sourced 10-band USER 1-10 layout with V2 0x21 save command. Save-only until physically verified. |
|
| FiiO BTR13 | Community-sourced 10-band layout with USER 1-3. Save-only until WolfEQ readback is physically verified. | |
| FiiO KA15 | Device profile, slot map, 10-band PEQ layout, USB EQ path. Needs real-device testing. | |
| FiiO KA17 | Device profile, slot map, 10-band PEQ layout, USB EQ path. Needs real-device testing. | |
| FiiO JA11 | Device profile, 5-band PEQ layout, core filter support. Needs real-device testing. | |
| Snowsky Melody | 10-band PEQ and USER 1-3 writes. Automatic EQ readback and Load from slot are disabled because the device does not answer the required read command. Readback remains unavailable by design. | |
| Snowsky Retro Nano | Product-name matched profile, slot map, 10-band PEQ layout. Needs real-device testing. |
For full Windows audio format support, set the K13 to UAC2.0 mode. FiiO documents that enabling K13 R2R PEQ limits playback to PCM 192 kHz/24-bit, disables MQA processing, and can briefly reconnect USB when switching between EQ Off and an active EQ mode.
The BR15 R2R, QX13, BTR17, and BTR13 layouts are adapted from the 0BSD-licensed DevicePEQ project and cross-checked against FiiO's published PEQ documentation. See THIRD_PARTY_NOTICES.md. Upstream configuration is evidence for an experimental profile, not a substitute for WolfEQ hardware verification.
K15, K17, and K19 are not listed as supported because their dedicated serial/RS232 control path needs a separate transport implementation. K11 R2R support likewise needs the separate WalkPlay protocol rather than WolfEQ's current FiiO HID handler.
- Preset, library, settings, online-profile, release-metadata, and installer sizes are bounded before parsing or saving.
- FiiO XML import prohibits DTD/entity expansion; imported numeric values are normalized to safe finite ranges.
- Local library, lighting, and BLE cache updates use atomic replacement to reduce corruption after an interrupted save.
- AutoEQ, OPRA, and application-update downloads are restricted to their expected HTTPS hosts and repository paths.
- Update downloads use unique temporary paths, enforce a 250 MB limit, and must have a Windows executable header.
- FiiO writes validate the device profile, writable slot, band number, filter support, numeric ranges, HID report size, and response timeout.
- Application logs escape line breaks, truncate oversized entries, and rotate at 5 MB.
- The bundled Equalizer APO installer is the unmodified upstream file. The release build refuses to package it unless its SHA-256 matches the pinned 1.4.2 value. Software EQ writes only
WolfEQ.txtand one marked block in Equalizer APO'sconfig.txt, using atomic replacement.
WolfEQ does not upload local presets or device data. Online search and update checks contact the providers named above. Installer code signing or published checksum verification remains recommended for a stable release.
This is beta software, and every profile except K13 R2R is intentionally marked experimental in WolfEQ. The BR15 R2R, QX13, BTR17, and BTR13 profiles begin in save-only mode: automatic readback and live writes stay disabled until their Windows HID behavior is confirmed on physical hardware.
If you test an experimental profile:
- Select the exact device model in Settings and use Reconnect device.
- Start with a flat or low-gain profile and an unused USER slot.
- Confirm the selected slot on the device before choosing Write to USER.
- Report the Windows version, device firmware, USB mode, selected slot, and whether the device stayed connected.
- Attach
%LOCALAPPDATA%\WolfEQ\logs\wolfeq.logwhen reporting a failure.
K13 controls still being explored:
- front-panel LCD text
- volume control
- EQ on/off switching
- NOS / OS / SAM mode switching
- optical and Bluetooth input switching
Please open an issue if something breaks or feels strange. Include your Windows version, device model, USB mode, and the exact preset/slot action you were doing.
git clone https://github.com/audioslayer/wolfeq.git
cd wolfeq
dotnet build WolfEQ.csproj
dotnet run --project WolfEQ.csprojRun the regression suite and dependency vulnerability audit:
dotnet test tests\WolfEQ.Tests\WolfEQ.Tests.csproj
dotnet list WolfEQ.csproj package --vulnerable --include-transitiveFor a local build-and-launch from a mapped drive or network share, use deploy.bat. It keeps WPF intermediate files under %LOCALAPPDATA%\WolfEQ\deploy-build so switching between drive letters and UNC paths cannot leave stale generated-source references.
If an older checkout reports missing Views\*.g.cs files, close any active build, remove the generated obj folder, and run the current deploy.bat again.
Build the installer with Inno Setup 6 installed:
.\build-installer.batMIT. See LICENSE for details.
Built by Tyson Wolf
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