Audio Latency Test
October 9, 2025 · View on GitHub
A comprehensive audio latency testing tool designed to measure and compare latency across different audio transmission protocols including Bluetooth, 2.4GHz wireless, and wired connections.
🎯 Overview
This project helps you measure audio latency in your setup by creating a feedback loop between your audio output and input devices. It's particularly useful for testing different audio interfaces, wireless transmitters, and processing software to understand their impact on overall system latency.
🔧 Setup Instructions
Prerequisites
-
Hardware Setup
- Connect your computer's audio output (line-out, audio interface, DAC, etc.) to your audio input (line-in, mic-in, interface, etc.)
- Ensure both the audio source and recording source are set as your primary audio devices in your system settings
-
Software Requirements
- Install PyAudio for Python audio processing
Running the Test
python runTest.py
The script will automatically run the latency test and display results. Simply wait for the test to complete.
📊 Key Findings
Note: Beacn is an audio processing software used during testing
| Component | Added Latency | Impact |
|---|---|---|
| Beacn Audio Software | ~0.15ms | Moderate impact from audio processing |
| Cable Length | ~0ms | No appreciable effect on latency |
| Atom Amp/Schiit DAC | ~0ms | No appreciable effect on latency |
| Scarlett Focusrite Interface | ~0.1ms | Small but measurable delay |
| 2.4GHz Transceivers | ~0.03ms | Minimal wireless transmission delay |
| Bluetooth Transceivers | ~0.18ms | Highest latency of tested protocols |
Summary
- Wired connections provide the lowest latency (~0.15-0.26ms)
- 2.4GHz wireless adds minimal overhead (~0.03ms additional)
- Bluetooth introduces the most significant delay (~0.18ms additional)
- Audio processing software can add noticeable latency (~0.15ms)
📈 Detailed Test Results
Without Beacn Audio Processing
| Test Configuration | Cable Length | Average Latency | Notes |
|---|---|---|---|
| Direct Connection (Line-Out to Line-In) | 82cm | 0.157ms | Baseline wired connection |
| Scarlett Focusrite Solo to Line-In | 609cm | 0.259ms | Interface adds ~0.1ms |
| Atom Amp + Schiit DAC to Line-In | 609cm | 0.164ms | Minimal impact from external DAC/Amp |
| 2.4GHz Transceiver (Atom Amp + Schiit DAC) | 122cm separation | 0.186ms | ~0.03ms wireless overhead |
| 2.4GHz Transceiver (Line-Out to Line-In) | 122cm separation | 0.187ms | Consistent wireless performance |
| Bluetooth Transceiver (Line-Out to Line-In) | 122cm separation | 0.340ms | Highest latency protocol |
Click to view raw test data
Direct Connection (82cm cable) - 10 tests
Average: 0.15654ms
0.14934ms, 0.15826ms, 0.15465ms, 0.15826ms, 0.15797ms
0.15789ms, 0.15511ms, 0.15702ms, 0.15871ms, 0.15825ms
Scarlett Focusrite Solo (609cm cable) - 10 tests
Average: 0.25939ms
0.25274ms, 0.25994ms, 0.26112ms, 0.25980ms, 0.25985ms
0.26102ms, 0.26027ms, 0.25819ms, 0.26131ms, 0.25968ms
Atom Amp + Schiit DAC (609cm cable) - 10 tests
Average: 0.16394ms
0.15477ms, 0.15806ms, 0.15777ms, 0.18646ms, 0.15719ms
0.16233ms, 0.15570ms, 0.15727ms, 0.16254ms, 0.18732ms
2.4GHz Transceiver (Atom Amp + Schiit DAC) - 10 tests
Average: 0.18552ms
0.18565ms, 0.18909ms, 0.18925ms, 0.15773ms, 0.18874ms
0.18962ms, 0.18812ms, 0.18942ms, 0.18869ms, 0.18894ms
2.4GHz Transceiver (Line-Out to Line-In) - 10 tests
Average: 0.18717ms
0.18063ms, 0.18684ms, 0.18901ms, 0.18502ms, 0.18892ms
0.18908ms, 0.18670ms, 0.19010ms, 0.18764ms, 0.18778ms
Bluetooth Transceiver (Line-Out to Line-In) - 10 tests
Average: 0.33987ms
0.34211ms, 0.32019ms, 0.32134ms, 0.34488ms, 0.32052ms
0.35162ms, 0.34641ms, 0.35065ms, 0.35130ms, 0.34971ms
With Beacn Audio Processing
The following tests were conducted with Beacn audio processing software active, showing the impact of real-time audio processing on overall system latency.
| Test Configuration | Cable Length | Average Latency | Latency Increase |
|---|---|---|---|
| Direct Connection (Line-Out to Line-In) | 82cm | 0.300ms | +0.143ms |
| Direct Connection (Line-Out to Line-In) | 609cm | 0.297ms | +0.140ms |
| Scarlett Focusrite Solo to Line-In | 609cm | 0.386ms | +0.127ms |
| 2.4GHz Transceiver (Line-Out to Line-In) | 122cm separation | 0.318ms | +0.131ms |
| 2.4GHz Transceiver (Scarlett Focusrite) | 122cm separation | 0.414ms | - |
| 2.4GHz Transceiver (Atom Amp) | 122cm separation | 0.310ms | - |
| 2.4GHz Transceiver (Atom Amp + Schiit DAC) | 122cm separation | 0.307ms | - |
| Bluetooth Transceiver (Line-Out to Line-In) | 122cm separation | 0.454ms | +0.114ms |
Click to view Beacn test data
Note: This data was collected before realizing Beacn's impact on latency, but provides valuable insight into real-world audio processing overhead.
Direct Connection (82cm cable) - 10 tests
Average: 0.29954ms
0.29785ms, 0.29702ms, 0.29984ms, 0.30855ms, 0.29951ms
0.29907ms, 0.29905ms, 0.29763ms, 0.29851ms, 0.29841ms
Direct Connection (609cm cable) - 10 tests
Average: 0.29654ms
0.29913ms, 0.29747ms, 0.29597ms, 0.29629ms, 0.29646ms
0.29572ms, 0.29437ms, 0.29628ms, 0.29654ms, 0.29716ms
Scarlett Focusrite Solo (609cm cable) - 10 tests
Average: 0.38600ms
0.38418ms, 0.38627ms, 0.38559ms, 0.38546ms, 0.38510ms
0.38624ms, 0.38834ms, 0.38666ms, 0.38559ms, 0.38660ms
2.4GHz Transceiver (Line-Out to Line-In) - 10 tests
Average: 0.31760ms
0.31504ms, 0.32019ms, 0.31887ms, 0.31990ms, 0.31993ms
0.31837ms, 0.31856ms, 0.30901ms, 0.31645ms, 0.31963ms
Bluetooth Transceiver (Line-Out to Line-In) - 10 tests
Average: 0.45386ms
0.45834ms, 0.45427ms, 0.45464ms, 0.45313ms, 0.45330ms
0.45330ms, 0.45264ms, 0.45381ms, 0.45214ms, 0.45304ms
🤝 Contributing
Feel free to contribute by:
- Testing additional audio interfaces and wireless protocols
- Improving the measurement accuracy
- Adding support for different operating systems
- Documenting your own findings
📝 License
This project is available under the terms specified in the LICENSE file.