Fully handmade Sonus Aeterna Zeus four way horn speaker from Greece with sensitivity 106 db/w/m and with 180.000€ price tag…
First way: Sealed box, bottom firing 18’’ subwoofer. Active and equalized 400W class D amplifier. Frequency response 16-100 Hz.
Second way: 100 Hz, pure circular tractrix horn. Double wall construction from carbon-kevlar-glass layers. Special internal damping. Loaded with 8” paper cone mid/woofer, as compression driver. Phase plug module. 1 meter diameter . Sensitivity 106 db/w/m. Frequency response 100-800 Hz. 1st order passive crossover.
Third way: 220 Hz, pure circular tractrix horn. Double wall construction from carbon-kevlar-glass layers. Special internal damping for the working freq. range. 2” compression driver. 50 cm diameter. Sensitivity 114db/w/m. Frequency response 800-8000 Hz. 1st order passive crossover. A special mechanism adjusts the angle and the critical phase delay of the driver.
Fourth way: Pure circular tractrix horn of similar construction. 1” ring radiator. Sensitivity 106 db/w/m. Angle and phase adjusted.