What a bass test tells you
Bass is where speakers lie the most. A small driver can fake the higher bass notes by playing their harmonics, but below roughly 60 Hz there is nowhere to hide: either the driver moves enough air or it does not. Stepping through the seven tones here maps your equipment’s real floor. On a laptop you will typically lose everything below 80 Hz; on a phone loudspeaker, below 200 Hz — which is why the 20 and 30 Hz buttons sound like silence with a faint flutter on most phones. That is not a broken file; it is physics.
On headphones the opposite applies: even budget in-ears reproduce 20 Hz as pure tone, because sealing a tiny driver against your ear canal is acoustically easier than moving air across a room. If 40 Hz sounds weak on headphones, re-seat the earcups or tips — seal lost is bass lost — before you blame the hardware.
How to listen
Set volume to a moderate level first — deep tones carry real energy, and pushing a small speaker to play 30 Hz at high volume produces distortion that can sound like rattling failure. Start at 40 Hz and work outward in both directions. Below your equipment’s limit you will hear the tone fade into either silence or a buzzy, strained noise; the transition point is your honest floor. Put a hand lightly on a speaker cabinet during 20–40 Hz: deep bass is physical, and feeling the panel move counts as reproduction even when your ears give up before your fingertips do.
Use the same seven tones to compare equipment fairly: play each tone at the same volume setting on your laptop, phone and headphones, and you will hear exactly what you are paying for when a spec sheet says “extends to 20 Hz”. When you find a speaker that plays a tone but adds buzz, the crackling fix guide explains the usual mechanical causes.