Sennheiser Builds 'Invisible Cities'

Invisible Cities, the world's first large-scale opera for wireless headphones, completed its run at Los Angeles' Union Station last month.
At the heart of the production was Sennheiser's new Digital 9000 wireless system.
The opera, a collaboration among The Industry, L.A. Dance Project and Sennheiser, was written by Christopher Cerrone and based on the 1972 novel by Italo Calvino.
The production included an 11-piece live orchestra being captured by a selection of Sennheiser and Neumann microphones, taking audience members on a journey throughout the terminal as character Marco Polo describes his quests to Emperor Kublai Khan
Three core technology elements from Sennheiser made the technical production possible: wired microphones; wireless microphones and IEM (in-ear monitoring) systems; and wireless consumer headphones.
Each instrument in the orchestra was miked using Sennheiser or Neumann wired microphones while performances were broadcast to performers and audience members using wireless technology. Audience participants were able to experience the entire performance using wireless consumer headphones from the Sennheiser RS 120 II system.
The Sennheiser Digital 9000 system delivered eight channels of uncompressed, artifact-free audio throughout the facility.
The components of the Digital 9000 system used in the opera included the EM 9046 digital receiver, SK 9000 bodypack transmitters and MKE 1 clip-on microphones.
"Digital 9000 was a natural choice for the singers," explains Dave Missall, National Market Development, Professional Systems, Sennheiser USA.
"In addition to delivering 24/96 kHz performance with unprecedented dynamic range and a non-existent noise floor, the Digital 9000 system made it easy to allocate frequencies in the middle of downtown Los Angeles, which is an extremely hostile RF environment. Since the Digital 9000 transmitters have very high linearity, intermodulation is non-existent. Therefore frequencies can be set in very close range to one another with no problems, making the system spectrum efficient."
Running in parallel with Digital 9000 was Sennheiser's 2000 series IEM system, which handled in-ear monitoring duties for each of the singers and dancers and ensured their performances were in lock step with the musical score. EK 2000 IEM receivers, IE 8 earbuds and SR 2050 IEM twin transmitters were accompanied by a highly complex antenna system, while four distinct zones throughout the terminal served as antenna farms to achieve seamless RF coverage for both the performers and for audience members wearing wireless headphones. Depending on the zone, A 2003-UHF passive directional antennas were deployed with A 5000-CP circularly polarized models, effectively minimising signal strength variations while eliminating multipath issues.
Sound designer Martin Gimenez specified Sennheiser evolution microphones as well as Neumann microphones to cover each instrument in the 11-piece orchestra.
Evolution microphones were used to capture brass and percussion, as well as overall room ambience. For woodwinds and strings, including the harp, Gimenez utilized several Neumann KM 184 small-diaphragm condenser microphones. On the piano, he selected a pair of Neumann U 87 Ai large-diaphragm condensers.
"Between the sonic immediacy of the headphone concept and Christopher Cerrone's haunting orchestration, sonic transparency was paramount on our minds," said Gimenez.
"Having access to the entire range of Neumann and Sennheiser microphones proved vital and necessary in order to convey the amount of detail to each and every audience member."
www.sennheiser.com
(IT/JP)