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

no inna.i meant 8 Meters but my keyboard is limited

Veroman, I see. 

Unfortunately, htshack.com seems to have removed most of its subwoofer test database.  By memory, I wanna say that the 8" subwoofers typically produced about 4 or 5% THD at 50hz at 85 DB (in a quasi-aechoic set up that effectively removes room nodes).  At 95 DB, that number more than tripled.  At lower frequencies, performance is much worse.  

Subs with larger drivers fared much better.  I switched from a pair of 8" Velodyne SPL(?) subs to a pair of Rythmik 12" subs and the A-B comparison was pretty compelling to me.  The ear is pretty insensitive to THD at these frequencies, but the sound "cleans up" in a very nice way with bigger drivers IME.

I'm pretty sure that there's a database out there somewhere with more detailed info, but I couldn't find it on a first search and I'm too lazy to do another.

An 8" woofer and 1" tweeter results in, "less than great music", in any sized room, IMO!

The crossover frequency is right in the middle of the midrange, and that is not optimal.

Go three way, or full range panel.

Don,

Most two-way, 8" woofer models that I’ve seen cross at 2200hz or higher, well above the middle of the mid-range. OTOH, lots of three way speakers cross to the woofer between 300 and 400 hz which is lower than middle of the mids, but closer. Maybe you’re just looking at a different set of examples than I did, but if you want your crossover out of the mids, I’d think you’d have a better shot choosing a random two way 8" over a random three-way model.

OTOH, lots of people think a x-over in that lowest part of the treble/presence region is worse than one in the midrange. I’d say that it’s Personal taste on that one.