walkplay-eqloader

An app for editing parametric EQ and pushing it to Walkplay-based USB DAC dongles (e.g. the Crinear Protocol Micro) without the vendor's app. It also generates EQ from headphone measurements with AutoEQ.

Runs on Linux, Windows, macOS, Android and in the browser. This is the Flutter rewrite of the original Python/Tkinter tool, which lives on in the legacy-tkinter branch.

In the browser, no install: devilapi.github.io/walkplay-eqloader (Chrome, Edge or Opera on a desktop computer; see Browser).

Or get the latest build from Releases:

dev-<number> releases are automatic builds of the latest commit and may be unstable.

Device support on Windows, macOS and in the browser is new and hasn't been tried on real hardware yet. If it works for you, or doesn't, please open an issue.

• Visual EQ editor: tap/click the graph to add a band, drag a handle to move it. Right-click (mouse) or long-press (touch) a handle to delete it. Values can also be typed in, and several selected bands can be edited at once.
• Filter types: Peaking (PK), Low Shelf (LSQ), High Shelf (HSQ), Low Pass (LP), High Pass (HP). Q can be shown as bandwidth in octaves.
• Device: push the EQ to any PEQ slot, load the current EQ back from the device, and enable/disable PEQ per slot.
• Profiles: save and load the .txt format used by EqualizerAPO and eq.hangout.audio.
• AutoEQ: pick a headphone/IEM model from the AutoEq database and generate EQ bands plus a clip-safe preamp, or load the profile the AutoEq project already computed for it.
• Undo/redo for all editor changes.
• Phone layout: the graph stays on top and the controls are split into EQ, Device, Files and Log tabs.

Open the web app in Chrome, Edge or Opera on a desktop computer. It talks to the dongle through WebHID, which Firefox, Safari and mobile browsers don't support; use the Android app on phones.

Plug in the dongle, open the Device section and click Connect Device, then pick the dongle in the browser's prompt. The browser remembers the permission, so on later visits the dongle shows up after Refresh List.

On Linux, the browser needs the same udev rule as the Linux app (see Linux).

Differences from the installed app: AutoEQ can only use the online database (no local folder), downloaded measurements aren't cached between visits, and saved profiles go to your downloads folder.

Install the APK and connect the dongle over USB-C / OTG. Android asks for permission to access the USB device the first time the app uses it; allow it.

Extract the zip and run eqloader.exe. No driver is needed; the dongle uses the built-in Windows HID driver.

Extract the zip and move eqloader.app to Applications. The app isn't signed, so the first time, right-click it and choose Open to get past Gatekeeper.

Extract the archive and run eqloader from the extracted folder.

Raw HID access needs a udev rule, so the app can talk to the dongle without root:

sudo cp linux/99-walkplay-hid.rules /etc/udev/rules.d/
sudo udevadm control --reload-rules && sudo udevadm trigger

Then replug the dongle. The rule file is linux/99-walkplay-hid.rules in this repository.

File dialogs use zenity (or kdialog), which most desktops already have.

Plug in the dongle and click Refresh List (F5); it appears in the Device list. In the browser, click Connect Device first. Select it to use it for all device actions. With several Walkplay devices, pick the right one or enter its PID.

On phones and small screens, Push EQ to Device and Load EQ from Device are also in the top bar, so they're reachable from every tab.

1. Tap the graph to place a band, then drag it, or type exact values in the Selected Filter panel. Changes apply immediately.
2. Pick the filter type in Type.
3. To edit several bands at once, Ctrl-/Shift-click them in the Filters list (long-press on touch); a changed field applies to all selected bands.
4. Set Slot, Preamp and Buffer and click Push EQ to Device. You're asked to confirm before the slot is overwritten.

The Protocol Micro always attenuates its output by a fixed 5 dB, set as Buffer (default -5). The device only stores the preamp beyond that, in whole dB: a preamp of −4.4 dB needs no extra attenuation, −9.6 dB is stored as 5 dB extra. Load EQ from Device reports the resulting preamp (stored value + buffer), so an exact preamp only survives through a saved profile file. If your device has no such buffer, set Buffer to 0.

Max filters (default 8) is the number of PEQ bands the device stores. Pushes are padded with inert 0 dB bands, because otherwise the device fills unused slots with copies of the last band. If the EQ has more bands than this, you're warned first: the device would silently drop the extras.

1. Click Compute AutoEQ (Ctrl+Shift+A).
2. The first time, choose Download Online Database (the AutoEq measurements on GitHub) or Choose Local Folder... with measurement .txt/.csv files. The choice is remembered.
3. Search for your model and select it. The same model often has measurements from several sources, shown in brackets. Downloads are cached. Browse File Instead... uses a single local file, Change Database... switches the source.
4. Pick a target: flat, a target from AutoEq's library (Harman, diffuse field, ...), or your own target file.
5. The generated bands and preamp replace the current EQ. Review them, then push.

Note: Computing AutoEQ yourself is an experimental feature. It works, but results can differ from what autoeq.app or hangout.audio produce for the same measurement. For a well-tested result, use Load Pre-computed AutoEQ instead.

Load Pre-computed AutoEQ (Ctrl+Shift+L) skips the optimizer: pick a model from the online database the same way, and it loads the ParametricEQ.txt the AutoEq project computed for that measurement. If there are several (one per target), you pick one. This only works for models from the online database.

The AutoEQ database is fetched from GitHub, so AutoEQ needs an internet connection; everything else works offline.

• Load Profile from File loads a .txt profile. OFF bands, zero-gain bands and duplicate bands are dropped.
• Save Profile to File saves the current EQ and preamp.
• To back up the device, use Load EQ from Device, then Save Profile to File.

PEQ Enable / Disable switches the device EQ on or off for a slot without changing what's stored, e.g. for A/B comparisons. Not all devices support this.

Shortcuts are also shown when hovering over a button.

The EqualizerAPO / eq.hangout.audio .txt format. Decimal commas and points both work.

Preamp: -6,0 dB
Filter 1: ON PK Fc 1000,0 Hz Gain 3,5 dB Q 1,000
Filter 2: ON LS Fc 80,0 Hz Gain -2,0 dB Q 0,707
Filter 3: OFF PK Fc 100,0 Hz Gain 0,0 dB Q 1,000

Filter types: PK, LS/LSC/LSQ, HS/HSC/HSQ, LP, HP. OFF bands and peaking/shelf bands with 0 dB gain are treated as disabled.

Walkplay-vendor HID devices (VID 0x3302). Tested on the Crinear Protocol Micro (PID 0xC20F). Other Walkplay dongles may work; please open an issue if yours behaves differently.

The Flutter app has no CLI yet. For pushing and pulling profiles from scripts, use eqloader.py from the legacy-tkinter branch.

Needs the Flutter SDK (stable channel).

flutter pub get
flutter test
flutter run                      # run on this machine
flutter build apk --release      # or: linux, windows, macos, web

Each desktop platform has to be built on that platform. Linux builds need clang cmake ninja-build pkg-config libgtk-3-dev.

Every push to flutter-rewrite builds all platforms and publishes a dev-<commit number> pre-release (dev-release.yml), and deploys the web app to GitHub Pages (pages.yml).