The Vienna Konzerthaus is the latest addition to a select group of world-renowned European concert halls that have chosen steerable Meyer Sound CAL column array loudspeakers. The Konzerthaus will use its new CAL systems for voice announcements, concert narrations, and incidental music. Other venues installed with CAL include Amsterdam's Concertgebouw, Konzerthaus Berlin, and another esteemed Viennese institution, the Musikverein.

"With CAL, we have excellent coverage of the entire hall with installation at one point," says Ingeborg Doblander, head of technical production for the Konzerthaus. "By placing both CALs behind the golden leaf grilles at the center of the venue, we solved the time alignment problems that were present in the old system. This resulted in in very good STIPA [Speech Transmission Index for Public Address] measurements."

The CAL systems were chosen following a rigorous evaluation process consisting of measurement and listening tests. "Several systems were brought in at different times, and no participants were given information about the others," reports Doblander. "We collected the data for each demonstration, and that served as the basis of our final decision in favor of CAL."

In the 1,840-seat Great Hall (German: Großer Saal), one-each CAL 96 and CAL 64 loudspeaker are both fully concealed in the organ loft behind a decorative grille. The advanced beam-steering technology in CAL allows the venue to custom-tailor both the vertical directivity and down-tilt angles with exacting precision. The CAL 96 loudspeaker is programmed in a split beam—an upper beam aims down at an 11-degree angle to cover the balcony with a 20-degree spread, and a lower beam aims down at a 24-degree angle to cover the lower floor with a 20-degree spread. The CAL 64 loudspeaker is aimed on axis with a 10-degree spread to cover the gallery.

In the 704-seat Mozart Hall (German: Mozartsaal), one CAL 32 loudspeaker is aimed down at a 10-degree angle with a 30-degree spread for balcony and floor coverage, while another CAL 32 loudspeaker is aimed on axis with a 10-degree spread to cover only the balcony. In addition, two MM-4XP and two MM-4XPD self-powered loudspeakers provide under-balcony and podium area coverage, respectively. Systems for both rooms were supplied and installed by Sommerein, Austria-based ATEC Pro Audio GmbH.

The systems both employ Allen & Heath iDR DSP and matrix mixers for signal processing and basic mixing capabilities. Other new equipment includes Sennheiser handheld wireless microphones with MMK 965 condenser capsules and Denon DN-700C CD players.

The Vienna Konzerthaus was first completed in 1913, reconstructed in the 1970s following the original Art Nouveau design, and completely renovated between 1997 and 2000. The Konzerthaus hosts the Vienna Symphony, the Vienna Chamber Orchestra, the Vienna Singakademie (choir), and a number of prominent music festivals.