The instrument
7 H-811B horn speakers and various drivers are mounted on steel tubes on a drum. The ensemble provided sound for a theatre in Basel.
Details
The Sectoral Horns H-811B from Altes Lansing are used for medium and high frequencies. It has a lower reinforcement limit of 800 cycles and is designed specifically for use in 2-way systems. The 804B Driver and N-8000 network should be used with this horn to provide high frequency pr0oduction from 800 to 22'000 cycles and also as a means whereby protection is afforded the HF driver from damage by low frequencies.
Low frequency cutoff: 800 cps;
Distribution: horizontal 90°, vertical 40°;
(Source: Altes Manual)