Klipsch Heresies and Cornwalls are great though enormous speakers. Very efficient. I have a giant Klipsch KLF C7 (2x8" drivers and a HUGE tractrix horn tweeter) center speaker which now integrates very nicely with a pair of M60 type Michaura M665s, a pair of QS8s on the sides and a pair of M2s on the back wall.

Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.