midrange speakers are anything form 3 inches to 8 inches. tweeters are the small ones, but some do make the mounting plate big, so they usually come in 1" or 3/4", some are 3" or 4". then the large speakers, 6 inch, 8 inch or 10 inch, will be midbass speakers or woofers. lastly the very large ones, 10", 12" 15" even 18", they are called subwoofers, they play the sub bass or very low frequencies.
some info i've got credits to cacin from gr8tunes.
50hz (usually sub bass)
this freq is where all the boom is, if you want more boom on foot drums and bass guitar, boost, to reduce, cut.
100hz( usually mid bass)
this is the hard bass sound, it gives drums that solid feel, boosting here will harden the drums/bass guitar, as well as adding warmth to guitars. A cut will reduce boom on guitar and add clarity.
200hz (either midbass/mid)
Boost to add warmth to vocals and guitar, reduce to clean up vocals
400hz (usually mid / large Horn)
Boost to bass in general, reduce to decrease cardboard sound low drums.
800hz(usually mid/horns)
Boost to add clarity and Punch to bass, this is the one that digs you in the ribs , cut to reduce tinnyness to guitars
1.5khz (mid/tweet/horns)
Boost to add clarity to bass guitar, reduce to impreve dullness of guitar
3khz (mid/tweet/horns)
Boost to increase pluck on bass guitar, attack on guitar and high drums, increases clarity of vocals.
Cut to reduce breathy sound on vocals.
5khz(mid/tweet/horns)
boost for vocal presence, low drum attack, piano attack, and guitars, reduce to distance background.
7khz(usually tweet/horn)
boost, more attack on low drums, percussion and bring life to dull vocals, also sharpen elctric guitar
Cut to reduce siblance
10khz (tweet/horn)
increase to brighten vocals/guitar and piano
cut to reduce siblance
15khz (tweet/horn)
increase to brighten vocals/guitar and piano highs