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Subwoofer test tones: how to test your sub at 30, 40, and 60 Hz

Play 30, 40, and 60 Hz sines one at a time and walk the room. Rattles, chuffing, and dead spots all show up clearly with a held pure tone that music never exposes.

Subwoofer test tones are pure sine waves at the low frequencies your sub actually reproduces. A 30 Hz tone checks your subwoofer's low-end extension, a 40 Hz tone probes the upper bass region where many systems and rooms interact, and a 60 Hz tone checks the crossover region. Playing them one at a time lets you listen for rattles, port noise, and room modes you can't hear in music because the bass is masked by everything else.

By TechCompare · Updated

Oscillators
1
Single tone
Frequencies
30 Hz
Waveform
Sine
Per-oscillator lanes

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How this is calculated

A useful subwoofer test isn't a sweep - it's discrete tones you hold long enough to walk around the room. Bass wavelengths are long (a 40 Hz wave is about 8.6 meters, or 28 feet), so the difference between a great seat and a null can be several decibels. Walk the room while a 40 Hz tone plays and you'll find the standing-wave peaks and dips your room correction system is fighting. The 30 Hz tone specifically checks excursion and port tuning - if your sub makes mechanical noises or chuffs at 30 Hz but not at 40 Hz, it's running out of linear travel or the port is undersized. The 60 Hz tone checks the crossover region and room modes.

Verdict

A minute with three pure sine tones tells you more about your subwoofer setup than an hour of music. Test 30 Hz for clean low-end extension, 40 Hz for the room's upper-bass resonance band, and 60 Hz for the crossover region. If you hear mechanical noise, port chuffing, or big dips as you move around the room, those are the problems music won't surface.

More Frequency Generator scenarios

Room resonance
Room resonance, also called room modes, is the standing wave pattern that forms in any enclosed space at low frequencies.
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Headphone rattle
A headphone rattle test isolates buzzing that music masks.
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Hearing test
This browser tone sweep can demonstrate which frequencies you can hear through your current playback setup.
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Related guides

Hearing test tone
A separate set of tones for checking hearing across higher frequencies.
View guide ➜
Beat frequency demo
Why beating tones matter when matching a sub to a room mode.
View guide ➜

Frequently asked questions

What Hz is best for testing a subwoofer?
30 to 60 Hz covers the subwoofer band that matters for movies and music. 30 Hz tests low-end extension and excursion, 40 Hz probes the upper-bass room interaction, and 60 Hz checks the crossover region. Hold each tone for 20 to 30 seconds and walk the room.
Why do I hear rattles with a test tone but not with music?
Music mixes bass with mid and treble content that masks small rattles. A pure sine tone has no overtones or other frequencies to hide the rattle behind, so any mechanical resonance in your room, furniture, or subwoofer grille becomes obvious.
Is a subwoofer sweep or discrete tones better for testing?
Discrete tones are better for finding specific problems like rattles and port noise. A continuous sweep run in compatible measurement software can show the overall response curve. This generator plays fixed tones, so use it for listening checks at selected frequencies.

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