Hi Ahal,
Maybe you should research these speakers: www.bloomline.com. I've heard them play and they really are amazing! No sweet spot anymore at all. Even when you walk around, the music seems to come from a stage between the speakers when you're walking by. This really amazing system was invented by Leo de Klerk, a recording engineer. Based on laws of fysics and audio behaviour.
Hope you'll find your perfect speaker. Success!