Free Speaker & Stereo Channel Test
Play short left, right or stereo test tones with adjustable frequency and low volume. Check audio channel routing locally without microphone access.
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How to use the speaker & stereo channel test
Play short left, right or stereo test tones with adjustable frequency and low volume. Check audio channel routing locally without microphone access.
- Set your operating-system audio output and start with a low volume.
- Choose the left, right or both channel setting.
- Adjust the frequency and volume, then select Play tone for a two-second sound.
- Compare the channels and use Stop tone immediately if needed.
Who needs a quick left and right speaker check
Stereo problems are easy to miss in everyday listening. A podcast sounds fine even when one earbud is dead, and a movie still plays when the speaker cables behind a TV are swapped. A short test tone sent to one side at a time makes these faults obvious within seconds.
This page helps people setting up new desktop speakers, gamers checking a headset before a match, musicians wiring studio monitors, and support staff confirming that a remote worker's audio output is routed correctly. It is also handy after plugging into an unfamiliar conference room system or a borrowed USB audio adapter.
A worked example: checking a new headset
Lower your system volume first. Choose left in the Channel menu, keep the frequency at the default 440 Hz and leave volume at 10 percent. Select Play tone. You should hear a steady pitch, the A above middle C, only in the left ear cup for two seconds. Then switch the menu to right and play again. The sound should move entirely to the right side.
Finally choose both. The tone should now seem to come from the center of your head. If the left test plays on the right side, the headset is on backward or the channels are swapped somewhere in the chain. If both tests sound identical and centered, a mono setting is probably merging the channels.
Try one more pass at 1,000 Hz. A higher pitch is easier to place, which helps when you are listening to room speakers a few feet away.
How the test tone is produced
The page builds a simple sine wave with your browser's Web Audio engine. The frequency slider runs from 100 Hz to 2,000 Hz in 10 Hz steps. The volume slider runs from 0 to 30 percent and sets the gain of the signal directly, so 10 percent is a gain of 0.1, roughly 20 decibels below full scale. The cap at 30 percent, about 10.5 decibels below full scale, is there to protect your ears and equipment.
The tone is routed through a two-channel merger. Choosing left feeds only channel one, right feeds only channel two, and both feeds each channel the same signal. Every tone stops on its own after two seconds, and changing any setting stops a tone that is still playing.
Nothing is recorded, and no microphone permission is requested at any point.
Common mistakes to avoid
Do not start with your system volume near maximum. Even a 10 percent tone can be loud through powered speakers or high-sensitivity earphones. Begin low and raise the system volume gradually.
Also check the obvious settings before blaming hardware. Many phones and computers have a mono audio accessibility option, and some Bluetooth hands-free modes send mono only. Confirm the correct output device is selected in your operating system, because the browser plays through whatever device the system has chosen. Finally, remember that a pure tone can sound uneven as you move your head in a room with hard walls; reflections, not a faulty speaker, often cause that.
Useful tips and limitations
- Mono audio settings and physical wiring can merge the left and right channels.
- This tool does not certify hearing or speaker frequency response.
- Very low frequencies near 100 Hz may be faint on laptop speakers and small earbuds, so use 440 Hz or higher for channel checks.
- When testing a surround or soundbar setup, remember this page sends only two channels, left and right.
Common questions
Does the stereo speaker checker need microphone permission?
No. It generates a tone locally through browser audio and does not request microphone input.
Can speaker-test tones continue indefinitely?
No. Every tone automatically stops after two seconds, and the Stop tone control ends it sooner.
What waveform does the speaker test play?
It plays a pure sine wave at the frequency you select, which gives a clean, steady pitch that is easy to locate.
Why does the tone stop when I move a slider?
Changing the channel, frequency or volume stops the current tone on purpose. Select Play tone again to hear the new setting.
Can this page tell me if my speakers are wired out of phase?
Not directly. It plays the same signal on both channels in the both setting, which can hint at a problem if the sound seems thin or vague, but it does not measure polarity.
Device checks and recordings run locally without AI or media uploads. Permission is requested only when starting capture. Download anything you want to keep before leaving the page.