DPA 4006 omnidirectional microphones have been used to record the organ at Passau, Germany, the world's largest cathedral organ, for a charity SACD in aid of the German Heart Foundation. The performance, by cardiologist Dr Hans-Joachim Trappe of Ruhr-Universit¿¿t Bochum, was recorded in stereo as well as in surround sound. The giant instrument, which is split into five sections throughout the baroque basilica, was a challenge for recording engineer and Tonmeister Ulrich Lorscheider, from German specialist classical recording company Aeolus. He chose to use mainly DPA 4006 and 4006-TL microphones for the recording, having worked with them in the past. "Here at Aeolus we are able to run two full surround recording setups simultaneously," says Lorscheider. "For this reason we own a large number of DPA 4006s as it is our main microphone of choice for this work, and they fully met my expectations again on this project. We particularly succeeded in reproducing the depth of the large cathedral in a three-dimensional way. The microphone setup was chosen mainly with a stereo mix in mind, but it delivered excellent results for the surround mix, too." The 10 DPA 4006s were used as main pair with a further pair for each of the two organs located on the left and right side of the main organ. A further two pairs were used as room mics for ambience: this provided two different 'layers' of ambience. "This was interesting as we could use them for both front and rear channels in the surround mix, which gave us a very nice rendering of the cathedral room," says Lorscheider. "As expected, in the stereo mix this arrangement proved to be very flexible, as we could make a choice of ambience situation according to the musical piece in question."