Humidifier has mysterious rumble and doesn't use as much water as it did Fixed

Client Comment: I have a smaller humidifier that works, but just doesn’t seem to put out water as fast.
I noticed a low rumble when the machine was set to low speed.
Spoiler: Evaporative humidifiers water use depends on air temperature and humidity content. Also: One of the fan mounting posts was broken, hence the rumble.