Stereo & Phase Tester

⚠️ Please lower your volume before playing any sound to protect your hearing.

LEFT
RIGHT

Ready

Channel Check

Phase & Panning

Phase check: In-phase should sound centered; Out-of-phase should sound hollow or 'wider'.

Frequency Test

Frequency test: Check if your hardware can reproduce low, mid, and high tones.

Stereo Tester | Verify Your Audio Balance & Phase

Audit your L/R channels, audio phase, and frequency response with professional-grade precision—directly in your browser.

💡 About This Tool

Fix imbalanced earbuds, verify speaker wiring, and diagnose setup issues instantly. This tool uses the Web Audio API to generate high-fidelity signals for testing spatial positioning, wiring integrity, and hardware frequency limits.

Whether you're setting up a home studio, unboxing new headphones, or troubleshooting a desktop setup, use these tests to ensure your audio is hitting your ears exactly as intended.

📘 How to Test Your Audio

Caution: Lower your system volume to a safe level before starting.

  • Verify Channel Mapping Click Left Channel and Right Channel to ensure your headphones aren't on backward and both drivers are firing correctly.
  • Identify Phase Issues Toggle between In Phase and Out of Phase. "In Phase" should sound centered and "solid." "Out of Phase" should sound hollow, wide, or like it’s "inside your brain." If the opposite occurs, your speakers or cables are likely wired with reversed polarity.
  • Audit Spatial Imaging Use the Panning Test to sweep sound from left to right. Listen for "dead spots" or sudden jumps in volume that indicate poor crossover settings or room acoustic issues.
  • Check Frequency Response Test your hardware's range with Bass (100Hz), Mid (1kHz), and Treble (10kHz). If the treble is silent, it’s a sign of hardware limitations—or a reminder to protect your hearing.

🧐 FAQ

Why does "Out of Phase" sound so disorienting? When audio is out of phase, the left and right sound waves partially cancel each other out. Your brain struggles to locate a physical source for the sound, creating that signature "hollow" or "pressure" sensation.

Does this work with Bluetooth? Yes. However, keep in mind that certain Bluetooth codecs and DSP (Digital Signal Processing) can introduce latency or minor phase shifts compared to a wired analog connection.

Can this tool fix my hardware? This is a diagnostic tool. It identifies problems like reversed wiring, blown drivers, or software balance issues so you can address the physical connection or system settings.

📚 The Tech: How Phase Works

In audio engineering, "Phase" refers to the alignment of sound waves. When two identical waves are perfectly aligned, they reinforce each other and increase volume. If one wave is inverted (shifted by 180 degrees), they cancel each other out, resulting in silence.

This principle is the foundation of Active Noise Cancelling (ANC). Your headphones listen to ambient noise and instantly generate an "Out of Phase" signal to neutralize it before it reaches your eardrums.