Ugg10 - you guessed almost spot on. If you have any inclination for the lottery numbers in this weekend's draw, maybe PM me? IME, I'd be looking at speakers with a 6 -7 " bass or bass/mid unit in each cabinet, or broadly equivalent cone area, so KEF 300 and KEF 500 would fit the bill though I can't recommend them as I haven't heard them. This is a generalisation based on my experience of using many speakers in many rooms but there are no solid rules and there may be exceptions. I once used a 45ltr closed box speaker with 8" Volt bass unit in a smaller room than yours but it kind of worked because it was a three-way active and had flexible L.F. EQ which I employed to reduce bass in that room.