d&b's variable acoustic solution for Barcelona's Granollers Theatre
A modern construction of concrete and glass, the Granollers Theatre Auditorium just north of Barcelona, Spain, has that special touch the Catalans can bring to such potentially lifeless materials. Drama, light and beauty from cold grey concrete, it's a neat trick. It is also very clever, graceful sweeps of vertical slabs along its flanks bring welcome shade to the glass walls. But lifelessness still managed to manifest itself in other, more acutely problematic ways. "The auditorium was very dry," said Head of Sound for Granollers, David Carrión. "Less than one second of reverberation is not a proper acoustic for the performances we wish to present." Fortunately Carrión has twenty years experience as a sound engineer and knew exactly what to do; install a surround system to support the acoustic. "We have established a system configured to provide three reverbs: 1.2 secs for jazz; 1.6 secs for contemporary classics; and 2.0 secs for classical."
Choosing the correct system was less obvious. "Apart from the reverberation issue, the chosen system had to be powerful and neutral enough to do any kind of show; from rock to theatre," continued Carrión. "It was critical that the design included well-placed sound sources to create correct virtual imaging for theatre. Our Technical Director, Jordi Tarrida, and myself invited an open contest to all brands. We eventually made our decision based on a number of important factors: live audition with an orchestra; acoustic studies and sound design; pricing; safety issues; size, weight, and special colour options and new technologies in both hardware and software. We chose a d&b audiotechnik system following all the comparisons and although pricing was a factor this was not the primary issue."
David Rosello of d&b audiotechnik Spain made the main system design, whilst local supplier Toni Puig of Sonostudi implemented the installation. Lars Frederiksen from d&b's Application Support team provided technical assistance for the reverb system. "The main PA is d&b's Q-Series in a Left/Centre/Right configuration," commented Rosello. "The reason to chose the Q-Series loudspeakers for the main system instead of d&b's Ci-Series installation based loudspeakers was to get as much gain before feedback as possible while working with the electronic acoustic enhancement system. However Ci80s were used on the sidewalls in a Left/Right/Rear surround configuration with further Ci80s mounted in the ceiling," continued Rosello.
Frederiksen took up the story "For the acoustic modifications, eighty percent of the focus is on the early reflections that helps create a feeling of spaciousness, which is what the audience found was lacking. The length of the reverb time is not so important in that context. But reflections (artificially created through the PA) at around 50μ ms are very important to create that feeling of space." A TC Electronics Rev 6000 controller was used to set the configurations, with d&b's proprietary ROPE C software controlling levels and some EQ. "The really clever thing about this system is that it provides the theatre with a variable acoustic. This enables them to support all kinds of performances with an acoustic suitable for the purpose," continued Frederiksen.
The concept of the electronic acoustic enhancement system in the Theatre Auditorium of Granollers is, to use a few superb quality pieces of equipment throughout the entire signal chain. Two Schoeps MK-8G microphones pick up the sound on the stage, which is then amplified by a GML 8304 pre amp before it is sent directly to the TC Electronics controller. From this the signal is distributed directly to the d&b D12 and E-PAC amplifiers, so no mixer is involved. Different presets have been created in the TC Electronics controller to provide acoustic enhancement for several purposes. The d&b amplifiers are remote controlled from the PC by d&b's ROPE C remote software, where presets have been created to switch between the acoustic enhancement configuration and other specific configurations for theatre, jazz, rock and other genres.
"I already had had experience with d&b equipment and knew its neutral character and power ability," continued Carrión. "But the remote capabilities of ROPE C proved a perfect control and system set up solution. In the tests we made live SPL measurements for multiple frequencies at many points around the auditorium to check coverage and imaging. Being capable of switching from one set up to another so easily was really important, and audiences have immediately noticed the improvements, and seem very happy".