I have the Vivid B1's which are powered by diy Hypex Ncore 300 watt monoblocks. I actually had to contact the dealer for room placement help and that made a night and day difference. Mine are about 2.5 feet from the back wall and completely open on the sides. They are toed in slightly about halfway compared to a direct toe in to my sweet spot. The sound is the best I have ever had in my room and I also have been in this hobby for a long time. I first heard class D Hypex Mola Mola monoblocks last year at CES in the Mirage powering the Vivid Giya's. It was some of the best sound I have heard and I knew I would soon build the diy Ncore version monoblocks. Very highly recommended with the Vivid's!
Jim
Jim