Sine wave generator

A single sine is one pitch with no harmonics. Use it when you want to hear a rattle at a specific note rather than a musical sound.

A tone generator’s job is one pitch, stable, with a stop button. Sine waves have no harmonics, so a rattle at 180 Hz is about 180 Hz, not about a bright buzz an octave up. Square and saw waves are full of harmonics and sound louder at the same slider position. They will also stress small speakers that shrugged off a sine. Start with sine unless you need the harmonics. The stop control sits on the same card as play, and it cuts the oscillator immediately.

Frequency here runs from 20 Hz to 18 kHz, and the slider is logarithmic so the octaves are not crushed into the top end. You can type a number. Changing it while the oscillator is running retunes the same oscillator instead of restarting, so a slow slide is a manual sweep. The high-frequency page starts high on purpose and keeps the warning next to the control.

Sweeps are scheduled on the audio clock from a start frequency to an end frequency. The default shape is exponential, which is how pitch feels. Keep them under half a minute. A sweep that passes through a rattle will make the rattle obvious, then the rattle will stop when the pitch moves on. That is the point. It is still not a plotted response.

White noise has roughly equal energy in every Hertz, so it sounds bright and hissy. Pink noise falls off so each octave carries similar energy, which is why people use it to match speaker levels by ear. Brown noise falls faster and sounds deep. None of these is a calibrated source. They are useful, and white noise in particular is tiring. Do not leave it running.

Pulses are short clicks at a tempo. They are better than a sustained tone when you are checking delay, because a click has an edge you can see against a video frame. The metronome range is intentional. Extremely fast clicks stop being a diagnostic and start being a noise.

Binaural beats are two tones, one in each ear, a few Hertz apart. The “beat” is not in the air. It appears when each ear gets its own tone, which means headphones, not speakers. Speakers mix the two tones acoustically and you get a normal beat you could have made with one oscillator. This page is not a treatment, a sleep aid with a claim, or something to use while you drive. Stop if you feel odd. The level cap still applies.

A missing high tone is not a diagnosis. It can be the driver, the volume cap on this page, your age, or a real hearing change. Only a clinician with calibrated equipment can test hearing. Do not turn a system volume to maximum to “find the limit.”

Low tones and subwoofer tones are there to move a cone a little, not to show off excursion. Laptop speakers will go quiet as the pitch falls, and that quiet is physics. A dedicated sub that stays quiet while the small speakers try to play 40 Hz means bass management is not sending that band to the sub. Turn the system down before you decide to “give it more.” Cone travel at home is how drivers get hurt.

Stop the generator when you have heard what you came for. A held sine is a tool, not a soundtrack, and a held noise is worse. If you are matching two speakers, use pink noise briefly and switch which one plays, rather than leaving both running until you stop noticing the difference. Square waves are for finding a buzz. They are a poor choice for a long listen on a small driver, because the harmonics ask the tweeter to work at every odd multiple of the note you picked.