Effective deepbass

According to Vienna’s statistics, the average theatergoer goes ecoconsciously by public transportation to theatres. Specifically to the Akademietheater, the second largest national theatre of the country, the interested parties just have to take the streetcar line 2. Plainly visible already from the Schwarzenbergplatz, the illuminated letters “Akademietheater” glow and indicate the way. In front of the main entrance with its three swinging doors, the bus line 4A drops off further visitors. And if you already have a ticket from one of the 6 box offices, only the assigned seat determines through which one of the nine radial arranged entrances you’ll ideally access the theatre hall. For example, if the visitor has its seat on the mezzanine, 22 steps lead there, from where one can overview the 192 square meters large stage, which is illuminated with over 40 power spots, and one can adequately listen to the well-balanced acoustic recordings. And this just owing to Christoph Keintzel, the director of the sound technology division of the Akademietheater, his team and the loudspeaker technology.

If Christoph Keintzel takes the shortest way from the sound control, and its 128 channels, way to the stage, the circular stairs are the appropriate option. Working in the field of sound technology for 22 years, he has taken the 14 steps of the circular stairs many times, and careered along the three steel doors of the corridor more than one can count, to pass one of two new effect subwoofers MF-15 in the end. Two single 15" subwoofers, each integrated at the right and left side of the stage back wall.

“There was a shootout between some providers in order to take the right choice, and there were some really heavy bass tools competing. At the beginning we all considered it impossible, that the now chosen subwoofer could convince here ever. 500 seats are really a lot”, tells Christoph Keintzel. “Especially in order to playback the acoustic theatrical effects, we required a very low corner frequency and a forceful tool. Combining these arguments with the little weight and tiny dimensions to flexibly operate with it on the stage, this product simply outdistanced the others.”

To keep the stage hindrance-free, the MF-15 were vertically integrated in the stage back wall, a circumstance which benefited the acoustic situation of this installation additionally. Normally low frequencies from single subwoofers radiate in all directions of the room spherically. But if the closed front corresponds only one dimension in which even the lowest frequencies can’t bend themselves around, the spherical sound source becomes a hemispherical one, a fact that results in an even higher level of efficiency and therefore even more output.

“Some time ago we had a French dancing group here, which initially pulled a long face upon the first sight of the subwoofers, because their dancing performance needed very high sound pressure levels, Christoph Keintzel remembers. A short while ago they came here again and in advance asked by telephone, if the same system was still installed, because they had been so pleased with it.”