40 Hz Tone
Continuous 40 Hz reference tone — play instantly in your browser.
Fixed frequency: 40 Hz (Sub-bass test)
Download a 40 Hz reference WAV (2 seconds, 44.1 kHz).
What this tool does
A 40 Hz tone vibrates 40 times per second. A deep sub-bass test tone for subwoofer and full-range system checks. This page locks the frequency so you can listen, compare equipment, or export a WAV without adjusting sliders.
How to use it
Tap Play to unlock audio (required on mobile browsers). Start at low volume, especially with headphones. Switch waveform to hear how harmonics change timbre while the fundamental stays at 40 Hz. Use Download WAV for an offline reference file.
Practical applications
40 Hz sits in the audible range for equipment testing and reference listening. Use it alongside our tone generator hub for nearby frequencies or our test tone download for offline files.
Frequently asked questions
Will my phone play 40 Hz?
Most phone speakers cannot reproduce 40 Hz meaningfully. Use headphones or a subwoofer.
What volume is safe?
Start low. Deep bass at high volume can damage speakers and hearing.
Last updated: September 2025. Technical values (Hz) are locale-invariant.