Speaker Test

Check your left and right speakers and stereo balance.

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Put on headphones or sit between your speakers, then press a button below. You should hear the tone only from the side you picked, or from both when you test both.

Phase test

Should sound centered and fuller, as if it comes from between the speakers.

BalanceBoth (0)

Test signal

Audio starts on your first tap on Play, as required by your browser.

A speaker test plays a tone through one channel at a time so you can hear which box answers. This left right speaker test, also called a stereo channel test or an audio channel test, adds a wiring polarity check and a balance sweep, so a crossed cable or a backwards speaker shows itself in about a minute.

On headphones? The guided headphone checks cover polarity, range and stereo image: Headphone Test

Running a 5.1 or 7.1 system? Test each channel on its own: Surround Sound Test

How to use it

Sit between your speakers, or put headphones on, and set a moderate volume. The test tone plays at a fixed level inside the page, so your system volume decides how loud it lands.
Press Test Left, then Test Right, then Test Both. Each button sends the tone to that channel alone, and the status line under the controls names the channel that is sounding.
Run the phase test. In phase sends the same tone to both sides; Out of phase flips the right side. The first should sit solid and centered, the second thin and hard to place.
Move the balance slider and press Play at this balance. Stepping it from full left through the middle to full right shows whether the image travels in one even line or jumps.
Change the test signal if you need to. 100 Hz, 440 Hz and 2 kHz are one tap away, and the number field takes any frequency between 20 Hz and 20 kHz.

What you can use it for

Checking a new setup. After wiring a pair of speakers, an amplifier or a soundbar, the channel test confirms that left really is left before you start listening to music and guessing.

Finding a dead channel. If one side stays silent, this test tells you the silence is real rather than a quiet passage in whatever you were playing.

Catching a speaker wired backwards. Reversed polarity is silent on its own: nothing rattles, nothing cuts out, the bass simply thins and the center image falls apart. The phase test is the fastest way to catch it.

Setting up a desk or a living room. Sweeping the balance by hand shows whether your seat is really in the middle, and moving the slider until the tone sits centered tells you how far off you are.

Chasing a buzz. Hold one channel at 100 Hz and press on the cabinet, the grille and the shelf. A buzz that stops when you press has a loose part behind it, not a broken driver.

Symptoms and what usually causes them

Symptom	Likely cause	What to try
No sound on one side	Cable, connector or one amplifier channel	Swap the two speaker cables at the amplifier. If the silence follows the cable, the cable or that amplifier channel is at fault; if it stays put, the speaker is.
Sides swapped	Crossed cables or a channel assignment	Press Test Left and follow the sound. If it arrives on the right, swap the cables or the output assignment in your system sound settings.
Both phase versions alike	One speaker wired backwards	Check the red and black terminals at both ends of both cables. Out of phase only sounds thin when everything else is wired the same way round.
Thin sound, no center	Reversed polarity, or a seat off to one side	Repeat the phase test while sitting exactly between the speakers. A solid center needs correct polarity and a symmetric seat at the same time.
Buzz at higher volume	Loose panel or a driver being pushed too hard	Lower the level and listen again. A buzz that grows with volume is usually mechanical; one that appears at a single frequency is a resonance you can hunt with a slow sweep.
Center pulls to one side	Balance setting or unequal distance	Set the balance slider to 0 and play both. If the tone is still off center, measure the distance from your seat to each speaker before you touch any setting.

Accuracy and limits

This is a listening test, not a measurement. It tells you which channel plays, whether the sides are the right way round and whether polarity is consistent. It says nothing about frequency response, distortion or how loud your speakers really are.

The browser hands the tone to your operating system, and everything after that is out of reach. A Bluetooth link, a system equalizer, an upmixer or a soundbar mode can move the sound between channels before it reaches a driver, so a strange result is worth checking against a wired output.

The phase test compares two versions of the same signal. It shows that one side is reversed relative to the other, but it cannot tell you which side, and it cannot see a reversal inside a sealed active speaker.

Frequently asked questions

How do I test my left and right speakers?

Press Test Left and check that the tone comes from the left speaker only, then Test Right, then Test Both. If a side is silent or the sound arrives from the wrong side, the cable or the channel assignment is the first thing to check.

Why do I hear the tone from both speakers when I test one?

Usually because something downstream is mixing the channels: a mono setting, a soundbar or upmixing mode, a Bluetooth speaker with one driver, or a laptop that sends both channels to the same tiny speaker. Try a wired stereo output before you suspect the wiring.

What does the phase test actually show?

Whether both speakers push and pull together. In phase should sound fuller and locked to the middle; out of phase should sound thin, wide and hard to locate. If the two versions sound alike, one speaker is almost certainly connected with the plus and minus reversed.

Which test frequency should I use?

440 Hz for channel checks, because it is easy to place and every speaker reproduces it. 100 Hz shows up buzzes and loose panels. 2 kHz is the most directional of the three, so it is the best choice when you want to hear exactly where the sound sits.

Do I need headphones for a speaker test?

No, and for a speaker test you should not use them. Headphones bypass the speakers you are testing. Use them only if you want to check the left and right sides of the headphones themselves, which the headphone test does in more detail.

Can a test tone damage my speakers?

Not at a sensible level. Damage comes from long, loud tones, especially very low or very high ones held at full power. Start quiet, raise slowly, and stop as soon as the sound breaks up or distorts rather than turning it up further.