PreSonus ERIS PRO 8 Active Coaxial 2-Way Studio Monitors - 8"The Eris Pro 8s coaxial design provides a single acoustic point source that creates a natural listening experience, revealing the subtlest nuances in your recordings. Combined with a punchy low end that defies its compact size, the Eris Pro 8 provides a superior listening experience for both home studios and professional mix rooms. A 1. 25 inch, ultra low mass, silk dome tweeter ensures snappy, accurate transient reproduction, while an 8 inch, woven