With the proliferation of outdoor amphitheatres in recent years, the onus increasingly falls on sound designers to integrate audio systems that are capable of performing in less-than-ideal conditions. In turn, it's up to manufacturers to provide these designers with state-of-theart technology through the development of powerful, controllable and versatile audio components. These advances in technology, combined with the creativity of designers, have led to dramatic improvements in lawn delay systems for amphitheatres, or "sheds." As any audio professional will attest, the obstacles associated with designing and implementing lawn delay systems are numerous. Inherent in any amphitheatre setting is the challenge of reconciling the loudspeaker system with the outdoor environment. In outdoor conditions, a number of mitigating factors are taken into account. "In some ways, it is actually more forgiving in outdoor spaces because there are less reverberant surfaces to deal with," said Brad Ricks, senior applications engineer at JBL Professional. "That said, in any outdoor setting, there will be environmental effects, such as air absorption. Because of this, it's important to design and install an audio system with enough power to counteract those dynamics."
Protection from the elements is another key issue when installing a lawn delay system. "In a lot of cases, the loudspeakers are installed in enclosures and will be removed at the end of the concert season," Ricks said. "Particularly in areas where humidity and precipitation are common, placing the loudspeakers in protective structures is beneficial to the preservation of the system."
According to Ricks, as the majority of shedstyle amphitheatres feature sloped lawn seating areas, the evolution of the line array has given sound designers a practical solution for providing even coverage across angles of varying degrees over large, open spaces. "Line arrays provide a good vertical coverage pattern that can be shaped to match the contour of the seating area," he said. "These outdoor amphitheatres are typically very wide, so it takes quite a few arrays to cover the entire area. However, the narrow coverage pattern and superior controllability of line array systems make them ideal for these environments."
This controllability of line arrays also plays a key role when discussing the issue of neighborhood noise ordinances. As many outdoor amphitheatres are built adjacent to residential areas, the ability to control noise levels is imperative to avoid complaints from the neighbors. "Dealing with the requirements of the neighborhood is always a challenge," Ricks added. "Care has to be taken to monitor the levels and limit the system. With line arrays, it's easier to cut off the pattern to avoid overshooting the back of the listening area."
Recently, Braintree, a Massachusetts-based Pro Sound Service, installed a new lawn delay system at the Tweeter Center in Mansfield, Mass., for the 2006 summer concert and event season. The Tweeter Center is a 19,900-seat outdoor venue with a covered, roofed section of about 7,500 seats, with the balance in an open seating area. A wall at the back of the seating area separates the venue from the community. The previous audio system, like the open-air venue itself, was 20 years old and was fatigued from continuous, hard-driving use.
Until the installation of the new system, there had been an ongoing noise complaint issue from the neighborhood located behind the back wall of the facility. A 16-foot-high wall barrier had been erected to alleviate noise complaints after the town established a maximum allowable sound pressure level of 95 dB SPL at the back wall. Sound levels are continuously monitored via a real-time calibrated measuring system with mics located at the top of the wall. Minute-by-minute SPL readings are printed for review by town officials, and a high priority is placed on containment of sound within the venue.
The final design for the system specified that each of four existing cluster locations would contain five VerTec VT4888 enclosures, with two additional locations, each housing VRX932LA compact constant-curvature line arrays and a single AM6212/95 cabinet as "fringe fill." The total system includes 20 VT4888 midsize line array elements, two AM6212/ 95s, and six VRX932LA's. Additionally, the system includes 11 Crown I-Tech 4000 amplifiers and 10 I-Tech 8000s, with two dbx 2231 dual 31-band graphic equalizers. JBL's VerTec Line Array Calculator software allowed the team to accurately predict not only coverage patterns, but SPL at various locations in the lawn area, along with rigging details. The new system is one of the first lawn-delay systems in the nation to use Harman Professional's HiQnet networking protocol and System Architect Software.
"During system commissioning," said Charles Tappa, president of Pro Sound Service, "with the system running at 95 dB SPL at the back wall, a handheld meter was taken into the neighborhood to check sound pressure levels. We made a phone call to verify that the sound system was still on because it could not even be heard in an area that was previously a problem spot in the neighborhood."
For the Bethel Woods Center for the Arts, in Sullivan County, NY, another outdoor facility, JaffeHolden, of Norwalk, Conn. designed a series of ten weatherproof custom speaker assemblies, each housing two loudspeakers weighing over 200 lbs. each. As the Bethel Woods Center sits precisely on the site of the original Woodstock festival, the loudspeakers needed to be able to compensate for the rolling topography of the local landscape. These loudspeaker assemblies are distributed under the rear edge of the pavilion roof, some 190 feet from the proscenium, to provide full-frequency coverage to the entire 70,000 sq. foot lawn seating area. Among the speakers chosen for this project were ten EAW KF750F speakers and ten EAW KF755Ps.
Beyond the 70,000 square feet inherent to the facility, the audience seats up to 12,000 people. Between these two factors, sound can be swallowed easily, necessitating an adequate mixing desk and proper amps to drive the speakers. For this, JaffeHolden selected a Yamaha DM1000 digital audio console and Crown amplifiers. Add to these the fact that Bethel Woods houses not only rock acts, but also classical and symphonic musicians.
"Most pavilions can only do one thing well," says JaffeHolden's Mark Holden. "Either they're designed for rock, or for symphonic music. We needed a pavilion designed for a new century." To this end, the walls and ceiling of the Bethel stage are designed to absorb the echoes and boomy sound that can compromise a performance with amplified music. For orchestral music, a portable, tunable orchestra shell was designed to JaffeHolden specifications.
Also newly installed in 2006, Overland Park, Kansas-based DSS, Inc. has designed and supplied the UMB Bank Pavilion in St. Louis, Mo., with a new lawn delay system featuring JBL VerTec line arrays. Live Nation, operator of the UMB Bank Pavilion, needed to upgrade the concert experience for guests who frequent the open-air venue to enjoy the many top-tier entertainment attractions hosted there. After repairing the older, existing lawn-area sound system year after year, the decision was made to purchase a new, more capable system. Increased fidelity, improved output capabilities and acceptance by visiting tour sound professionals were design goals.
The new system, as installed by DSS, includes 24 VerTec VT4888 midsize line array loudspeakers, supplemented by nine VRX- 932LA compact constant-curvature loudspeaker systems. The array coverage pattern and output power capabilities of the JBL speakers were a key aspect of this application, due to the venue's large seating capacity, which totals more than 13,000.
"We've achieved excellent results with JBL VerTec systems in our company's touring and rental division, and it's a natural fit as well for installations of this type," advised Jeremy Dixon, of DSS. "Such installed lawndelay systems must complement the touring sound rigs brought into outdoor amphitheatre venues during the summer season. The new installed system at UMB Pavilion is meeting both their needs and those of venue management."
