Oris 150

About the Oris 150

The BD-Design Oris 150 is a high-efficiency two-way biamped speaker system featuring front-loaded Lowther horns with PM4AER drivers and Onken bass cabinets. The horns measure approximately 77-78 cm in diameter and 60 cm in length, with a natural tuning frequency around 150 Hz. The system achieves a sensitivity of about 105-108 dB at 1W/1m, making it suitable for low-powered SET amplifiers, ideally in the 1mW to 500mW range. The bass cabinets typically use 10-inch woofers built to Bert Doppenberg's plans, rolling off around 170 Hz, complementing the horn-loaded mid/high frequencies. The speakers are praised for their micro and macrodynamics, transient response comparable to planar or ribbon drivers, and a clean, open sound with stable imaging and deep bass down to below 30 Hz. The Oris 150 requires painting for optimal performance and is often paired with high-quality Lowther or AER drivers, though some users have success with Fostex or Tangband drivers. The system is DIY-friendly and allows for tuning and customization. The The speakers are not small but have an appealing aesthetic and are considered a high-end, efficient horn system for audiophiles.