Speakers that like corners

Klipschorns

There are some which a google search should locate. There are also some good speakers designed for mounting in the wall. The classic Tannoys and several American brands of the time worker that way and there are more modern designs available. Probably the easiest place to look would be among the good home theater speakers;many of them are designed for wall placement. K Horns are WAY too big, some of their other ones might work. Don't dismiss wall mounting, it has several advantages.

I have KHorns in a room about your size and they work about as well as any other I've had in there. I love the extra room I have now because the KHorns are tucked into the corners and out of the floor. May or may not be right for you.