Speaker Test (Left / Right Audio Test)

Check that your speakers or headphones are connected the right way round and working on both sides. The test clips play a tone on the left only, the right only and both together, check whether one speaker is wired out of phase, pan a tone from left to right, and sweep through the bass and the whole audible range. All clips are generated in your browser.

How to use this tool

1. Turn your volume down, then press Calculate if the clips are not shown yet.
2. Play "Left channel": you should hear it only on the left. Then "Right channel".
3. Play "Both channels" (it should come from the middle) and "Phase check" (the second half should sound wider and thinner).
4. Choose the sweeps to test bass response, rattles and your hearing range.

Formula

Log sweep: f(t) = f₀ × (f₁ ÷ f₀)^(t ÷ T) · Constant-power pan: L = cos θ, R = sin θ, θ from 0 to 90°

Tones are 440 Hz (left), 660 Hz (right) and 550 Hz (centre) so you can tell them apart. In the phase check the right channel is inverted for the second half: correctly wired speakers then sound diffuse, while a reversed speaker makes the inverted half sound fuller. Pink noise has equal energy in every octave (Paul Kellet's filter on white noise).

Example

The full sweep rises from 20 Hz to 20 kHz in 20 s, about one octave every 2 s, so 1 kHz arrives at 20 × log(1000 ÷ 20) ÷ log(1000) ≈ 11.3 s. If the tone fades out at 17 s, the limit is 20 × 1000^(17 ÷ 20) ≈ 7.1 kHz: try other headphones or speakers to tell whether the limit is the equipment or your ears.