QSC im Planetarium in Jena

Jena, Germany (November 2012) – CX Series amplifiers and AD-S loudspeakers from QSC have helped to revolutionise the sound systems at Germany's oldest planetarium, creating an aural experience that is literally out of this world.

The Zeiss Planetarium in Jena, eastern Germany, opened in 1926 and is the oldest such building to have remained in continuous service since that time. The projection dome stands 14.5 metres high and has a diameter of 23 metres, resulting in an impressive projection surface of around 800 square metres. In 2006, the outmoded projection system was replaced by a full-dome video projection system, which was brought into full operation during the last lengthy phase of reconstruction in autumn 2011 with the addition of eight digitally controlled video projectors. To perfect the visitor experience, the planetarium's owners decided to make the aural treats match the visual, and a high-quality 3D sound system was built into the projection dome of the planetarium in cooperation with QSC and the Fraunhofer Institute.

The audio sources used in the planetarium's presentations are digitised, processed by powerful PCs in real time, placed in a 3D soundstage and manipulated, and then converted back to analogue signals before being passed to the loudspeakers. Up to 64 analogue signals at once are then passed to the total of 16 QSC CX254 four-channel amplifiers to as many as 60 two-way QSC AD-S82H loudspeakers, while four subwoofers take care of the lower frequencies.

46 of the 60 full-range speakers are located in the gallery, the remaining 14 behind the perforated metal covering of the dome. Because the dome is not quite a perfect circle, and is slightly flatter at the sides, the seating faces a particular direction rather than being concentric. The sound systems take account of this; near the front of the dome the QSC AD-S82Hs are also closer together than at the rear, because human hearing is better at picking up sounds coming from the front than the rear.

It could be argued that in this kind of public building, where the experience is primarily a visual one, such a detailed sound system is an unnecessary extravagance. Until you see and hear the Zeiss planetarium in action, that is. Thanks to the hard work of the engineers who have brought together QSC technology with that of the Fraunhofer Institute, the visuals and audio mesh seamlessly, creating a breathtaking experience in which you can pick out every aural and visual detail. As Jürgen Hellwig, the planetarium's Director is fond of pointing out, it can't be a coincidence that the Zeiss in Jena recorded a record number of visitors for a single month after the newly installed systems were opened to the public.