01
What this can prove
The tool can document a self-reported low-frequency observation, save a known-good listening baseline, and compare two runs with identical signal settings.
Subwoofer test
Low-frequency references
Play one short reference at a time. Begin with a low device volume and record what you hear before changing the path.
Before Play: Lower the physical volume. Do not raise it to make 20 to 40 Hz audible. Stop if you hear strain, a loud rattle, or anything uncomfortable. This stereo browser signal is not a discrete LFE-channel test.
If you hear nothing but the ordinary speaker test works, run the 440 Hz path check below. It uses this page's audio engine but does not test your subwoofer. Then try 160 Hz upper bass at the same low physical volume. If 440 Hz plays but bass stays silent, check your speakers, output, connection, and equipment's own test tone or bass-management settings. Silence alone does not prove a fault.
Starting points
The playable signal is limited to 20–200 Hz, at or below −30 dBFS, with a short duration and fades. Digital level is not sound pressure.
Audio readyWeb Audio is unavailable in this browser.
Keep or continue this check
The record contains settings, timestamps and self-reported outcomes, not raw audio or device identifiers. No data is uploaded. A portable ZIP contains the selected generated reference, not your observations.
Check whether a short bass reference is present, absent, weak, intermittent, or rattling in the current complete playback path.
Start at a low device volume. No sound starts automatically. Use Stop all audio at any time.
02
What it cannot prove
It cannot measure frequency response, SPL, room modes, crossover frequency, absolute polarity, a discrete LFE channel, or a failed component from listening alone.
03
Privacy and safety
Signals and analysis stay in your browser by default. Browser dBFS is not physical SPL.
How to use this test
- 01
Start low
Lower the physical volume first. Do not turn it up just because a very low tone is inaudible.
- 02
Record one reference
Play a short tone or sweep, stop, and record only what you heard at your normal listening position.
- 03
Change one factor
Repeat the same reference after one safe placement, setting, connection, or source change. Record both results for an exportable comparison.