@larryi You nailed it, that's exactly how I would describe the Zu Omens I auditioned. Loud and dynamic yes, but also a bit sibilant, thin and edgy. I love loud music (peaks around 90db) but these were speakers I wanted to turn down and became fatiguing at higher levels. A polarizing speaker for sure. I found the Heresy IV much closer to my taste, and ultimately settled on the Forte. Not really a fair comparison price wise, I probably should have compared at least the Union to the Heresy, but if you've heard some of their higher end models like the Druid and Definition and still feel that way, I doubt I would have liked the Union.
