I owned Heresy's for many years. As Sean says, they'll play loud...that's the good news. The bad news is that they are mid-range forward and light on the bass. Your room is pretty big so you may not get below 60Hz. A sub is needed especially for rock. In a 20x25 room Dunlavy's should work well. I've heard the Cantata and Aletha and both are worth a listen and wouldn't need a sub (these speakers have great bass, actually the best I've heard).
Oh, by the way, listen to Kelly's advice on the Avant Garde's. My ears, too, are bleeding. Dave
Oh, by the way, listen to Kelly's advice on the Avant Garde's. My ears, too, are bleeding. Dave