You have what is likely a good room acoustically. Symmetry and the naturally present large reflecting surfaces (e.g. alcoves), smaller diffusing surfaces (e.g. bookshelves) and absorption (e.g. curtains, furniture, carpet, false ceiling,…), floor and wall construction, etc… will have an influence though. How good a room is acoustically has nothing to do with speakers.

Speakers would need to be appropriately sized to deliver clean sound at standard levels when the listening position is 4m+. away (unless you only listen 1m away at a desk of course). Normal 3 way tower speakers with a pair of 8" woofers should be fine. A 2 way desktop speaker with a 5" midwoofer would not be and even with subwoofers there may well be a hole in clean SPL in the crossover region where music tends to have a lot of energy.