Speaker Test — Balance & Polarity
Online speaker test with left-right pink noise, 1 kHz tone, balance walk and polarity check with mono sum. Find wiring faults fast. Free in your browser.
Protect your hearing. Start at a low volume. Never raise the volume to make a tone audible. Levels are shown in dBFS, relative to full scale — not SPL.
How it works
Pink noise is generated in an AudioWorklet and a 1 kHz sine is generated with the Web Audio API. Each channel has its own gain path: the right path can be inverted, and a mono sum adds the two paths together. With one channel inverted, the summed output cancels to near silence, which the level meter measures in dBFS. Nothing is uploaded or recorded, and no sound plays until you ask for it.
A speaker test checks three things about a stereo system: that each speaker makes sound, that the two are balanced in level, and that they work together in the correct polarity. Play pink noise or a 1 kHz tone on one channel at a time to confirm each speaker, run the balance walk to compare left, both, and right in a repeating loop, then invert one channel and switch on the mono sum to hear out-of-phase content cancel to near silence. Everything runs live in your browser, and nothing is uploaded or recorded.
Left / right speaker test
Choose Left, then Right, and confirm the sound comes from the expected speaker. If the two are swapped, a cable or an operating-system setting is reversed. Isolating each side is also the fastest way to catch a dead driver, a blown tweeter, or a loose connection.
Speaker balance test
Pink noise is the recommended balance signal because its energy is even across every octave, so any tonal difference between the speakers is easy to hear. In the Both setting a correctly balanced pair should sound like one centred, even image. If one side is louder, your balance control or a driver is off; the level meter shows the combined output as you switch sides.
Speaker phase and polarity test
Polarity is about whether both speakers move in step. When the same signal reaches the two channels with one inverted — out of phase, or 180 degrees apart — the waveforms are mirror images. Summing them together, which is what a mono system or a single summed output does, adds each positive peak to a negative peak of the same size, so the result is near silence. Switch on the mono-sum button and toggle the inversion: the level meter drops by a large margin and the readout states the cancellation when the channels cancel. When the channels are in phase, the same sum doubles instead, and the meter shows reinforcement.
Aliases covered on this page: speaker test, speaker polarity test, speaker phase test, speaker balance test, and left right speaker test.
Frequently asked questions
How do I test my speakers?
Play the pink noise or the 1 kHz tone on Left, Both, and Right in turn. Each side should be clearly audible from the matching speaker, and Both should sound centred and even. Pink noise reveals tonal balance; the 1 kHz tone is the reference for level and presence.
What is a speaker polarity or phase test?
Polarity describes whether both speakers push and pull in step. When one channel is inverted against the other and the signal is summed to mono, the two copies cancel and the output drops to near silence. This tool plays one channel inverted and lets you switch the mono sum on and off to hear and see the cancellation.
What is the mono-sum button for?
A mono sum adds the left and right channels together, the way a mono playback device or a single speaker hears them. With both channels in phase the sum reinforces; with one channel inverted the sum cancels. Watching the level meter drop when you invert polarity in mono is a direct check of relative polarity.
Why does out-of-phase content cancel?
When two identical signals are added with one inverted, every positive sample meets a negative one of the same size, so they sum to zero. This is the same physics that makes a speaker wired backwards sound thin and hollow when summed with its twin.
Which signal should I use for a balance check?
Pink noise is the classic balance signal, because it carries equal energy per octave and sounds even across the room. The 1 kHz tone is easier to localise by ear and is the standard reference for confirming that a channel produces sound at all.
Is this safe for my hearing?
Start at a low volume and never raise the volume to make the signal audible. The tool plays only from a user gesture, provides a persistent Stop and Mute, and reports levels in dBFS, relative to full scale, never in SPL. Pink noise and a 1 kHz tone can both become uncomfortable quickly at high levels.
How do I test my iPhone speaker online?
Open this page in Safari, set volume low, then play the left, both and right pink-noise checks in turn. Each side should sound clear from its speaker and the centered signal should sit in the middle. If one side is quiet or distorted at modest volume, clean the grille, then compare on headphones to separate phone faults from track issues.