The SB-AFP1000 was an audio flat-panel speaker developed by examining as many as 80 types of test models and thoroughly performing computer simulations. The speaker used a unique twin-cabinet system with both sealed sections and open sections present at the same time in one cabinet. The speaker included eight 30-cm x 80-cm flat units for the low frequencies and four 13-cm x 32-cm flat units for the lower midrange frequencies. In particular, the diaphragm area for the low frequencies was equivalent to a cone woofer with a diameter of 152 cm, and at 124 dB the speaker attained amplitude of 1.27 mm (at 50 Hz). This enabled bass reproduction with low distortion. Characteristic of the AFP was that the bass was emitted in flat waves, and so the system was resistant to adverse effects such as due to indoor refection, and attenuation due to distance was extremely low. As a result, powerful, deep bass extended to the far corners of the space, and the listener was able to feel the subtle air fluctuations with his entire body. The cabinet was given a black-coating mirror finish. The first Audio Flat Panel AFP1000 was delivered to the world renowned Vienna State Opera House for use in playing the performances of singers and orchestras during rehearsals. The modular construction of the AFP System allowed creation of various combinations from "wall to wall" systems to downsized models such as the SB-AFP100 and SB-AFP10.