A -3dbFS sweeping sine tone, from 10Hz (supposedly inaudible) to 200Hz (supposedly played back by all sound systems, including those smallish laptop speakers). On the top of the test tone, a voiceover tells you which frequency is currently playing.
Humans hear frequencies from 20Hz up to 20.000Hz. The lowest bound, 20Hz, with a wavelength of nearly 20 meters, is a frequency we feel rather than actually hear. Because of their increased wavelength, low frequencies generally require fairly large speakers. However, the closer your ears to the source, the smaller the required speaker size. This is why headphones, despite their small size, have no trouble playing back the low frequencies. This test helps you benchmark the lowest bound of your audio system’s frequency extension.
I did not make this test.
Post time: Nov-27-2017