Knowing what is meant to happen during a cycle makes it much easier to tell whether it is working, and to stop at the right point rather than guessing.
For a complete overview, see the two-stage cleaning method.
Seconds 0 to 5 — engagement
The tone starts and the diaphragm begins moving through its full travel. If liquid is
present the tone often sounds slightly dull or damped at first — the water is adding mass and
restricting movement. This initial dullness is itself a useful diagnostic: a tone that starts
clean suggests there may be no liquid to remove.
Seconds 5 to 20 — the threshold
This is where most of the work happens. Accumulated displacement exceeds the surface tension
holding the film together and it fragments into separate droplets. Many people hear the tone
change character here — becoming cleaner and slightly louder without touching the volume. That
change is the single best indicator that the mechanism is doing its job.
Seconds 20 to 60 — transport
Freed droplets are pumped outward by the alternating airflow, biased by gravity. You may see
visible moisture appear on the grille surface. This is why orientation matters so much: grille
down means each droplet leaves and keeps going, held flat means it sits beside the opening.
Between cycles — the wipe
Blot the grille area dry before starting the next cycle. Expelled water left on the surface
gets drawn back in on the next intake stroke, which is why two cycles with a wipe outperform
three run back to back.
Cycles two and three
Diminishing returns are normal and expected. The first cycle handles the bulk; subsequent
ones catch what was held in less accessible parts of the cavity. If the second cycle produces a
noticeable further improvement, a third is worth running. If it produces nothing, stop.
Reading a failed cycle
A tone that sounds identical from start to finish, across three cycles, means the mechanism
is not engaging. Either there is no liquid present, or the obstruction is not the kind that
responds. Continuing past that point only heats the voice coil.