In a 14 x 35 room the 2809 should do nicely to get much more spl you would have to look at seperate amps and have at least double wattage. so far as clarity, it is up to the speakers to do that not the amp.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70