Five checks, five minutes: channels, polarity, bass reach, treble reach, and distortion. Put your headphones on, set a moderate volume, and work down the list - new pairs, used pairs, and "something sounds off" pairs all take the same test.
Each side should play alone, at equal volume. A missing or weak side points at the cable, a blocked grille, or OS balance settings.
The centered tone should image exactly in the middle of your head - off to one side means unequal drivers or balance.
Compare the two buttons. In-phase should sound fuller, bassier, and locked to the center; if inverted sounds better, one side is wired backwards.
Out-of-phase headphones cancel bass and image diffusely - most common after a cable repair or replacement.
A 15-second sweep from 100 Hz down to 20 Hz. Note where the tone becomes inaudible - good over-ears and sealed in-ears reach 20-30 Hz.
Weak bass on in-ears is usually a broken seal, not the driver - reseat with larger tips and sweep again.
A 15-second sweep from 8 kHz up to 20 kHz. The point where it vanishes is usually your hearing ceiling, not the headphones.
Compare against your hearing age result before blaming the hardware.
Steady low tones at a healthy level. A clean sine should sound perfectly smooth - buzzing or crackling means debris or a damaged driver.
A hair on the driver buzzes exactly like a torn one - clean the grille before writing off the pair.
Wireless pair? Measure its delay with the latency test - codecs range from 40 to 300 ms and decide whether video and games stay in sync. Weighing a used pair, or want the full reasoning behind each check plus the buying checklist? The long-form headphone testing guide covers it. And since the treble sweep ultimately measures you, not the hardware, bookmark your ceiling with the hearing age test and re-check it yearly.
Five checks: left and right play separately at equal volume; a centered tone images in the middle of your head; the in-phase signal sounds fuller than the inverted one (polarity); slow bass and treble sweeps play smoothly to the extremes without dropouts; and bass tones at moderate volume sound clean, without buzzing or crackling. This page runs all five - a pass on each means the pair is functionally healthy.
In rough order of likelihood: a blocked earwax filter or grille on that side, a damaged cable near the plug or earcup (wiggle it while the tone plays - crackling confirms it), OS balance settings shifted off-center, or a failing driver. A steady test tone makes the left/right comparison far more reliable than music.
Correctly wired headphones play both drivers in the same polarity: the in-phase button should sound solid, bass-rich, and centered in your head. If the inverted button sounds fuller or more natural instead, the wiring is reversed on one side - typically a miswired replacement cable or repair. Out-of-phase headphones lose bass and image diffusely.
Good over-ears and sealed in-ears produce audible output down to 20-30 Hz; open-backs and budget earbuds often start at 40-80 Hz. With in-ears, weak bass is 90% fit: a broken seal dumps everything below 100 Hz - try larger tips and reseat before blaming the drivers. The treble ceiling you find is usually your ears, not the hardware; compare with your hearing age result.
On bass tones a torn or rubbing driver buzzes clearly - but so does a hair or debris caught in the driver, which is common and fixable (clean the grille gently). Test at moderate volume: a clean sine should sound perfectly smooth. Buzzing that persists after cleaning on both 40 and 60 Hz usually means driver damage.
Generate single tones with precise frequency control. Perfect for quick audio testing and tuning.
Play multiple frequencies simultaneously with independent volume and panning controls.
Create linear or exponential frequency sweeps for speaker testing and room acoustics analysis.
Generate binaural beats for meditation, focus, and relaxation. Requires headphones for proper effect.
Generate telephone dial pad tones (Dual Tone Multi Frequency). Interactive touch-tone dial pad.
Professional metronome with tap tempo, time signatures, subdivisions, and tempo trainer for musicians.
Tap along to any song to find its tempo in beats per minute. Includes tempo markings reference.
Hear major, minor, diminished, and seventh chords in every key. Block chords or arpeggios.
Hear classic progressions like I-V-vi-IV and 12-bar blues in any key at any tempo.
Free browser piano with 3 octaves, note names, and computer keyboard support.
Generate white, pink, and brown noise for sleep, focus, tinnitus relief, and speaker burn-in.
Reference tuning notes for guitar, bass, ukulele, violin, cello, and more at concert pitch (A440).
Test your subwoofer with a 60-second frequency sweep (150Hz-1Hz) and individual bass test tones.
Test your hearing range from 8kHz to 20kHz. Find your hearing age and compare with averages.
Ancient healing tones including 528Hz (DNA repair). For meditation, chakra activation, and spiritual healing.
Test stereo balance with panning control and left/right channel testing. Perfect for speaker setup.
Check speaker wiring polarity by comparing in-phase and out-of-phase test signals.
Measure your Bluetooth or system audio delay in milliseconds with a click-and-flash sync test.
Real-time frequency analysis of your microphone input with a live log-frequency display.
Measure approximate sound levels with your microphone - live dB with min/avg/max tracking.
Check your microphone in seconds: live waveform, level meter, and record-and-playback check.
Learn to recognize musical intervals by ear with quiz mode, score tracking, and song mnemonics.
Chromatic pitch pipe with all 12 notes across 3 octaves. Perfect for singers, choirs, and a cappella groups.
Experience the auditory illusion of an infinitely ascending or descending tone. Mind-bending psychoacoustic phenomenon.
Can you hear the mosquito tone? High-frequency test (15-20kHz) that only young people can hear. Find your hearing age!
Create relaxing ambient soundscapes with singing bowls, nature sounds, and binaural beats.
Push water out of a wet phone or watch speaker with a pulsed 165 Hz tone - the same method Apple Watch uses.
Adjustable high-frequency whistle (8-22 kHz) for dog training - clearly audible to dogs, silent to most adults.
Rhythmic pulsed tones across delta to gamma ranges. Stronger than binaural beats and works without headphones.
Name 12 random notes with no reference tone and find out if you have absolute pitch or great pitch memory.
Sing your lowest and highest notes and get your range plus voice type - bass to soprano. Mic-based, nothing uploaded.
Find the highest frequency you can hear (8-20 kHz) and see how old your ears test. Takes one minute.
Send noise to each 5.1 channel - fronts, center, surrounds, and subwoofer - and catch swapped or dead speakers.