Curious about how often pick your monitors the sound? Here is a handy video that you can test this spectrum. This is useful to know for example if you work a lot with an equalizer (EQ).
The wave begins at 20 Hz and ending at 20000 kHz. The sound will gradually increase with constant values. If you do not hear anything below 40-50Hz, your monitor may not be able to bring to the hearing at the lowest frequencies.
at certain frequencies you might want to turn up your sound, this is because you do not hear it. Pay attention to your ears, because it can then go very hard which can cause hearing loss and hardware damage.