Spatial 3D audio for competitive gaming on Windows.
Precise direction, clean footsteps, tamed gunfire — on any headphones, no virtual cable.
Shooters such as Battlefield and Call of Duty output 7.1 surround. On headphones you normally hear a flattened stereo mix, so enemies "behind" and "in front" sound alike. TacAudio turns the game's 7.1 into binaural 3D audio using measured head-related transfer functions (HRTFs), like commercial headphone virtualisers do — and then goes further for competitive play:
- Combat dynamics pull down gunfire, explosions and killstreak audio while lifting quiet sounds, with a punch control so gunshots keep their impact.
- Footstep clarity lifts the footstep "crunch" band only while a channel is quiet, so loud gun cracks in the same band are not boosted.
- No hidden bass boost: the subwoofer channel is passed at the level the game mixed it, with an optional bass slider.
TacAudio's engine runs inside Windows' own audio processing on your headphones (Direct mode): the game simply plays to your headphones in 7.1, there is no virtual cable, and it adds about 4 ms of delay. Everything is adjustable live while you play, from a modern dark app with a tray icon and hotkeys.
| 🎯 Direct mode | Engine built into Windows audio on your headphones: no virtual cable, ~4 ms delay, keeps working with the app closed |
| 🎧 Measured heads | SADIE II KEMAR and Neumann KU100 dummy heads included (+18 human heads optional), diffuse-field equalised so they sound neutral |
| 👂 Find your head | 2-minute listening test: enemy footsteps (boots on gravel, like in a game) walk from 8 directions through each head, you click where you heard them, TacAudio picks the head with the most accurate directions and fewest front/back mix-ups |
| 🏠 Room presets | Neutral (dry, most precise), Balanced (small room), Spacious |
| 🔫 Combat dynamics | Light / Medium / Strong, per channel and before 3D (a gun on one side never ducks footsteps behind you) |
| 👣 Footstep clarity | Quiet-only 3.5 kHz clarity boost, 0 - 12 dB. Smart mode lifts only short impacts (steps, landings, reloads) and leaves steady sounds in the same band (rain, wind, engines) alone |
| 🎮 Game profiles | Game library (Steam + Epic found automatically, others added by hand) with each game's own sound; switches when the game comes to the front |
| 🎚️ Headphone EQ | Import a parametric correction for your headphone model (Equalizer APO / AutoEq format, file or paste); applied after 3D, in both modes |
| ♿ Footstep ring | Accessibility option (off by default): a small click-through ring in any corner of the main screen (or the centre) glows towards enemy footsteps. Your own sounds (straight ahead), explosions and loud gunfire are ignored; a Detection setting picks how sure it must be: Sensitive (every step-like sound), Balanced (from the 2nd step, ignores single shots and automatic fire) or Strict (steady walking only, also ignores reloads). Check your game's / tournament's rules before using it competitively |
| 🔁 A/B switch | 3D on/off instantly (Ctrl + Alt + F9) to compare against plain stereo |
| 🧭 Setup assistant | Installs the engine on your headphones and shows live whether your game is sending 7.1 |
| 📊 Performance page | Live level of each of the game's 8 speakers, how much loud sound is tamed and quiet sound lifted |
| 🖥️ Everyday app | Tray icon, start with Windows, global hotkeys, per-option reset buttons, update check |
| 🔌 VB-CABLE mode | Optional fallback for setups where Direct mode can't be used |
- Download
TacAudio-Setup-0.7.6.exefrom the Releases page. - Run it. It installs for your user only into
%LOCALAPPDATA%\Programs\TacAudio, with a Start menu entry and an uninstaller in Settings → Apps.
Until code signing is in place (see Code signing policy), Windows SmartScreen may warn you. Click More info → Run anyway.
TacAudio's Setup assistant opens on first launch (and any time from the Setup page):
- Choose your headphones.
- Install engine — Windows asks for administrator permission once; sound pauses for a few seconds while Windows audio restarts.
- Set up your game: audio output = your headphones (or the Windows default), and in the game's audio settings choose 7.1 / Surround / Home theater. Turn off the game's own 3D-headphone mode.
- Check: start the game — the assistant shows "Your game is sending 7.1" when the back and side channels arrive.
Tested with Call of Duty: Modern Warfare 4 on a GoXLR Mini: full 7.1 arrives, no anti-cheat issues.
Good to know
- The engine processes everything played on that headphone device (Discord, browser...). Stereo apps stay stereo and pass through the same sound settings.
- Windows' Audio enhancements must be enabled for the device (the default).
- Apps that use exclusive or "raw" audio mode bypass Windows' audio effects, and therefore TacAudio.
- Remove engine in the Setup assistant (or uninstalling TacAudio) restores the device's original Windows effects exactly.
If Direct mode can't be used, the Setup assistant's VB-CABLE tab walks you through the older
path: the free VB-CABLE virtual device set to 7.1, the game playing
into CABLE Input, and TacAudio capturing it and playing to your headphones (~25 ms delay).
It detects the cable and its 7.1 setting, opens the right Windows dialogs and runs an inaudible
8-channel test (tacaudio-cli cable-test does the same from the command line).
| Page | What it's for |
|---|---|
| Sound | Head (with the Find your head test), room, combat dynamics + punch, footstep clarity, volume and bass, live meters. Every option has a ↺ reset button; Reset all restores the defaults |
| Profiles | Your games as a library of covers. Give a game its own profile (start from Default or another profile); TacAudio switches to it while that game runs and back to Default when it closes. Edits on the Sound page go to the active profile |
| Devices | Where the engine is installed (Direct mode), or source / output devices (VB-CABLE mode), and the headphone EQ (Find your headphones opens AutoEq, download the "Equalizer APO" parametric file, Import file) |
| Setup | Setup assistant: Direct mode (recommended) or VB-CABLE |
| Performance | The game's 8 speaker levels, streams, how much loud sound is tamed / quiet sound lifted |
| Settings | Start with Windows, turn on at launch, close to tray, hotkeys, accessibility (footstep ring: position, size, opacity), update check (asks GitHub for a newer release at launch and twice a day; a banner links to the download, nothing installs by itself) |
| Hotkey | Action |
|---|---|
Ctrl + Alt + F10 |
TacAudio on / off |
Ctrl + Alt + F9 |
3D sound on / off (A/B) |
Closing the window keeps TacAudio running in the tray; right-click the tray icon to exit. In Direct mode the engine keeps your last settings even when the app is closed.
flowchart LR
G[Game<br>7.1 output] --> W[Windows audio engine<br>audiodg.exe]
subgraph W2 [TacAudio APO inside Windows audio]
D[Combat dynamics<br>+ footstep clarity<br>per channel] --> H[HRTF convolution<br>7 virtual speakers]
D --> M[Room<br>early reflections + FDN]
H --> S((+))
M --> S
S --> V[Volume, 3D A/B]
V --> L[Peak limiter]
end
W -->|7.1, 8 channels| D
L -->|stereo| O[Headphones]
A[TacAudio app] -.->|settings| W2
W2 -.->|levels, status| A
Direct mode. Windows lets audio-effect add-ons (Audio Processing Objects, the same mechanism
behind "Audio enhancements" and laptop virtual-surround features) process a playback device.
TacAudio installs one on your headphones. It asks Windows for a 7.1 input while the device stays
stereo, so a game set to 7.1 delivers all 8 channels to TacAudio, which renders them to 3D stereo
right before the headphones. The app writes the settings to %ProgramData%\TacAudio\apo.ini (applied
within 0.1 s) and reads the engine's live status back.
The engine:
- Dynamics: each channel is compressed above a threshold and lifted below another, using a blend of peak and ~30 ms loudness detection (punch). Footstep clarity adds a 3.5 kHz band only while the channel is quiet.
- Spatialisation: every channel is a virtual speaker at its 7.1 position, convolved with the chosen head's HRTF pair (uniformly partitioned FFT convolution). The direction-averaged response of each head is equalised flat, so the head's own ear resonance does not colour the sound.
- Room: a stereo send feeds early reflections and a 4-line feedback delay network with a Hadamard matrix; bass and top end are kept out of it so footsteps stay clean.
- Output: volume, 3D on/off and a look-ahead peak limiter.
Live changes (head, room, dynamics...) swap the whole renderer without clicks: the new one runs silently for ~20 ms to fill its filters, then crossfades in over ~10 ms. The audio thread never allocates, locks or waits; renderers are built on a worker thread.
VB-CABLE mode uses the same engine in the app: WASAPI loopback capture of the cable into a lock-free ring buffer with drift compensation and an adaptive buffer, then exclusive-mode output.
| Result | |
|---|---|
| Added delay, Direct mode | ~4 ms (one 2.7 ms processing block + 1 ms limiter look-ahead) |
| Added latency, VB-CABLE mode | ~25 - 31 ms exclusive output, ~55 ms shared |
| 7.1 through Direct mode | 8 channels arrive discrete (test levels -30 ... -51 dBFS intact) |
| CPU | ~2 % of one core |
| Gunfire vs. footsteps (battle test scene) | 31 dB → 21 dB (medium) → 16 dB (strong) |
| Gunshot crack kept with punch 60 | 32 dB vs. 34 dB without dynamics (24 dB at punch 0) |
| Footstep detector (ring): footsteps / rain / gunshot / explosion / silence | 0.90 / 0.03 / 0.00 / 0.00 / 0.00 |
| Smart footsteps: steady band noise / footstep bursts | classic +4.5 / +4.3 dB, smart +0.0 / +4.0 dB |
| Raw MIT KEMAR average at 2 - 3 kHz | +17.8 dB → flat within ±1.5 dB after equalisation |
Requirements: Windows 10/11, Visual Studio 2022 or 2026 with the C++ workload and Windows SDK, CMake 3.25+, Python 3 (only to download head data). The configure step downloads zlib, libmysofa and Dear ImGui.
cmake -S . -B build -A x64
cmake --build build --config Release
build\Release\tac_tests.exe # unit tests
build\Release\tacapo-setup.exe selftest # drives the APO in-process
python tools\fetch_sadie.py # SADIE II KU100 + KEMAR (--all: + 18 human heads)
build\Release\TacAudio.exeInstaller (needs Inno Setup 6):
powershell -ExecutionPolicy Bypass -File scripts\build_installer.ps1
# -> dist\TacAudio-Setup-<version>.exeThe GitHub Actions workflow (.github/workflows/build.yml) builds, tests and packages the
installer on every push, and publishes a GitHub Release for every v* tag.
tacapo-setup status # where the engine is installed, live levels, log
tacapo-setup install --device "Headphones" # (administrator) install the engine on a device
tacapo-setup uninstall # (administrator) remove it, restore the original effects
tacapo-setup play71 --device "Headphones" # quiet 8-channel test tone (levels show in status)
tacrender demo renders # synthetic 7.1 test scenes -> binaural WAVs
tacrender render in_71.wav out.wav # any 5.1 / 7.1 / 7.1.4 WAV -> binaural
tacrender heads # list head sets; tacrender audition <dir>: one render per head
tacaudio-cli devices # audio devices with periods
tacaudio-cli run --loopback "CABLE Input" --out "Game" --exclusive # VB-CABLE mode engine
tacaudio-cli cable-test # verify a virtual cable carries 7.1src/core/ DSP, no dependencies: FFT, partitioned convolver, HRTF sets + diffuse-field EQ,
VBAP, binaural renderer, room, dynamics, limiter, ring buffer, varispeed, WAV
src/engine/ real-time engine for VB-CABLE mode (drift compensation, adaptive buffer)
src/platform/ WASAPI capture / loopback / render (shared, low-latency, exclusive)
src/sofa/ SOFA HRTF import (libmysofa)
apps/apo/ TacAudioApo.dll (the Direct-mode engine inside Windows audio) + tacapo-setup.exe
apps/common/ CLI helpers, AudioSession, cable check, apo_control (app <-> engine)
apps/tacaudio_gui/ TacAudio.exe: Win32 + Direct3D 11 + Dear ImGui app (ui_widgets = UI kit,
profiles = game profiles, game_library = Steam / Epic scan + covers)
apps/tacaudio/ tacaudio-cli.exe apps/tacrender/ tacrender.exe
tests/ unit tests (each DSP block against a reference; engine vs. offline; drift, jitter)
tools/ make_icon.py (app icon), fetch_sadie.py (head data)
installer/ Inno Setup script scripts/ build_installer.ps1
docs/SIGNING.md code signing setup .signpath/ SignPath artifact configurations
- Upmix for stereo-only games
- Code-signed installer (SignPath Foundation, applied for)
What changed in each version: CHANGELOG.md (also in the app: About › What's new).
TacAudio uses the SADIE II HRTF database (University of York, Apache-2.0), the MIT KEMAR HRTF measurements (Gardner & Martin, MIT Media Lab), libmysofa, zlib and Dear ImGui. See THIRD_PARTY_NOTICES.md.
TacAudio's own code is released under the MIT licence. Third-party components keep their own licences (see above).
Free code signing provided by SignPath.io, certificate by SignPath Foundation (applied for; until then releases are unsigned).
Only release builds made by this repository's GitHub Actions workflow are signed, and each one is approved by hand. See docs/SIGNING.md.
TacAudio does not collect or send any personal data. The only network request it makes on its
own is the update check: a plain request to the GitHub API for the latest release
(api.github.com/repos/sa3oodi/TacAudio-engine/releases/latest), at launch and twice a day. It
can be turned off in Settings (Check for updates). Buttons such as Download VB-CABLE or
Find your headphones only open a web page in your browser when you click them. Recordings made
with Record 15 s of game sound stay on your PC.
TacAudio is an independent project. It is not affiliated with or endorsed by DTS / Xperi, Dolby, Microsoft, SteelSeries, VB-Audio or any game publisher. All trademarks belong to their owners.