Do we really need anything more than 8" woofer and 1" tweeter for medium size room?

What's a medium sized room? Not having a dedicated midrange driver makes crossover points a bit challenging, often times putting the crossover just where music and our hearing are most sensitive..

My room is roughly 2010 cu ft "they" list is at med here 
3ways can be quite pricey when done well imo .. 

Let's say medium size room is 300sqf with 10ft ceiling. Everything is challenging when you want things to be done right.

Im 13.5'x16'x10'. 
4 gik traps two low on corners of sprks wall 4' from spkr long wall two high behind my sofa one 24x42 in each reflection wall  1 12x42 above my large curtain window behind me.. Money well spent . Took My low-end to another level . All spkrs and sub on audiopoints 

Ok,  to push the discussion a little further... In reality,  you can design an 8 inch 2 way to be somewhere around 3db down at 35 hz and still go out to 2k to blend with a tweeter. Of course,  every 8 cannot do this... Way back, I had a peerless woofer that had enough excursion that when adding enough mass, it could go comfortably down to the mid 20's in a sealed box,  but it would loose its mid performance.  We did use it occasionally as a sub, never developed or used it in big numbers.  So,  you can definitely, get an 8 inch woofer to go down. The big deal that has already been discussed is that as the driver gets larger, it can move a substantial amount of air.  I have hear 15 inch 2 ways that I could live with, but didn't go down any lower than a decent 8, yet the difference in impact of the air moving along with the added sensitivity was a great experience.