subbass (low notes), are usually considered 80hz frequencies and below. - deeep pipe organ, low piano notes, some electric\string bass, techno, the 'rumbly' deep kind of bass, ect.
midbass (middle notes on the low end) are usually considered 80~400hz frequencies - kickdrums, cello, electric\string bass, the 'punchy' kind of bass.
midrange (upper middle notes) are usually considered 400~5khz frequencies - human male voice, some lower end female voice, drums, guitar, most of the music is here
highs\treble\tweet (high high notes on the teeny weeny itsy bitsy strings /end strongbad) are usually considered 5kh~20hz and above - cymbols, guitar on the tiny little high strings, female voices, violin, and all that, the kind of sound that makes your ears hurt, aka - treble.
those are just rough numbers, and can be argued to be lower\higher\broader\whatever... im not POSATIVE on the midbass\midrange numbers, but im sure they are close to those numbers.
this chart is kinda cool;