Presets

What Each Preset Is For

440 Hz is the international tuning standard: play it against an instrument, tuner, or your own ear to check for drift. For the exact frequency of any other note, the note frequency chart covers the full range at 432, 440, and 444 Hz references.

1 kHz is the standard reference tone for level calibration: it's the frequency most meters, monitors, and calibration tools are tuned against, so it's the tone to use when you're setting a baseline playback level rather than checking tuning. Once levels are set, the LUFS meter checks loudness on real material against streaming targets.

The subwoofer test tones (25 to 60 Hz)are built for the classic subwoofer crawl method: place the sub temporarily at your listening position, play one of these low tones through it, then get down at floor level and crawl around the room listening for where the bass sounds fullest and least boomy, not simply loudest. Wherever that spot is on the floor is roughly where the room's low-end response is smoothest, so that's where the subwoofer should permanently sit. Test with more than one of the low presets, since a single frequency can hide a room null that only shows up at a slightly different one.

The frequency sweeps ramp continuously across a range instead of holding one tone. The full 20 Hz to 20 kHz sweep is useful for scanning the whole audible range for dead spots or resonances, and the 20 to 200 Hz bass sweep isolates the low end, where most room modes and rattles actually live. Listen for any point where the volume jumps, buzzes, or sets something in the room rattling; that frequency is worth investigating further.

Waveform

Sine vs. Square for Testing

A sine wave contains energy at exactly one frequency and nothing else, which makes it the right default for tuning, level calibration, and anything where you want a clean, unambiguous signal. A square waveis built from that same fundamental frequency plus all of its odd harmonics (3x, 5x, 7x, and on), so it carries far more high-frequency energy for the same fundamental pitch. That extra harmonic content is exactly why square waves are good for hunting rattles: a buzz might not show up on the fundamental alone but will show up on one of the harmonics riding on top of it. The tradeoff is that square waves sound noticeably harsher and louder-feeling than a sine wave at the same volume setting, and they're rougher on both ears and tweeters, so start quiet.

Triangle and sawtooth sit on either side of that line: triangle rolls its harmonics off faster and sounds closer to a sine wave, while sawtooth includes every harmonic, not just the odd ones, and comes across even harsher than square.

Honest limits

Human Hearing Range: What This Tool Can and Can't Tell You

20 Hz to 20 kHz is the commonly quoted range of human hearing, but that's a nominal figure for young, healthy ears, not a fixed ceiling. Sensitivity to the highest frequencies declines steadily with age: most adults over 40 struggle to hear much above 15 to 16 kHz, and that ceiling often drops further by 60, regardless of how sharp their hearing feels day to day. Playing the 10 kHz preset or running the full sweep will give you a rough sense of where your own high end starts to fall off.

That said, this is not a calibrated hearing test. The result depends entirely on your speakers or headphones being able to reproduce those frequencies accurately in the first place, on your playback volume being consistent, and on background noise in the room. If you have genuine concerns about your hearing, see an audiologist rather than relying on a browser tone. If you've generated a tone and instead need to identify the frequency of an existing sound or recording, the frequency detector does that in reverse.

Frequently Asked Questions