Audio Channel Test
Find out whether both channels actually work. Isolate left and right, sweep the full audible range, and listen for dead drivers, weak sides or swapped channels.
Channel isolation
Each button plays a 1 kHz tone into only the selected output. You should hear silence on the other side.
Speaker identification
A slow alternating voice announces each side. Confirm you hear left on the left.
Frequency sweep
20 Hz to 20 kHz over 30 seconds, logarithmic. Listen for any silent band, rattle or hiss.
Noise
Turn the volume down before starting. Pink reveals hum and imbalance; white reveals hiss at the top end.
Tone reference
Steady tones for spotting distortion at a specific frequency.
How to test your speakers or headphones
- Set a low volume and plug in the device you are testing.
- Press Left only. Confirm the sound comes from the left.
- Press Right only. Confirm the sound comes from the right.
- Run the full sweep and listen for gaps, rattles or hiss.
- Play pink noise on both sides and compare the loudness.
What each test finds
| Test | What a fault sounds like |
|---|---|
| Left / Right only | Silence on one side means a dead channel, a loose plug or a muted balance slider. |
| Announcement | The wrong side means the channels are swapped in software or cabling. |
| Frequency sweep | A silent band at the low end is a blown woofer; crackle at the top end is a tired tweeter. |
| Pink noise | One side louder means an imbalance; a hum at 50 or 60 Hz means ground loop noise. |
| White noise | Rasping at the extreme top end points to clipping in the amplifier. |
Common causes of one-sided sound
- Headphone plug not fully inserted into the jack.
- A single-ear headphone with a shared cable and a broken conductor.
- Operating system balance set to centre on one channel.
- Bluetooth headphones connected in mono mode.
- A failing driver, which usually fades at high frequency rather than cutting out entirely.
Audio channel test limitations
- Your ears are the measuring instrument here. For a truly accurate check, swap devices and compare.
- Bluetooth adds its own compression and delay, which can mask small faults.
- Built-in laptop speakers cannot isolate channels, so use headphones for a real channel test.
- Very low frequencies are felt more than heard, so judge the sub-bass by rattle rather than pitch.
Safety
Start low and raise slowly. Sustained pink noise and full-volume sweeps can cause hearing fatigue, and cheap headphones can distort loudly at high volume. Stop if you feel discomfort.
FAQ
How do I know which side is left?
Play the Left only test and look straight ahead. The sound must come from the left speaker or left ear cup. If it comes from the right, the channels are swapped.
What is the frequency sweep for?
The sweep plays every audible frequency in turn, from 20 Hz to 20 kHz. A gap in the sound, a rattle or a hiss pinpoints a bad driver or a loose connection at that frequency.
Why should I turn the volume down first?
Pink noise and the sweep both put real power through a headphone driver. Starting at a low volume avoids a blast of noise through open headphones and keeps your ears safe.
What does pink noise sound like?
Pink noise sounds hissy and even across all frequencies, like wind or rain. Unlike white noise, which is bright and piercing at the top end, pink noise has equal energy per octave.
Is my audio uploaded anywhere?
No. Every tone and noise burst is generated by the Web Audio API inside your browser and played straight to your speakers or headphones.