dv-dosc a breakaway success at st. pete times forum
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News | DV-DOSC A Breakaway Success At St. Pete Times Forum

TAMPA, Florida -- St. Pete Times Forum, home to the NHL’s 2004 Stanley Cup Champion Tampa Bay Lightning, recently installed a turnkey L-ACOUSTICS system comprised of 66 dV-DOSC enclosures, a dozen dV-SUB low-frequency extension boxes, eight SB218 sub-bass cabinets and four ARCS® boxes, all powered by LA48a amplifiers.

Originally known as the Ice Palace, the arena first opened its doors in 1996 as the new downtown Channel District home for both the Lightning and five-time AFL Arena Bowl-winning Tampa Bay Storm. Aside from hosting home games for these two major sports teams, the multipurpose facility also brings in a wide array of other events, including high-profile concerts by artists like Paul McCartney, U2, and the Rolling Stones, NBA exhibition games, USF Basketball and NCAA Tournament games, tennis, professional wrestling, boxing, figure skating, rodeos and circuses.

According to Pollstar, St. Pete Times Forum ranked as the number one venue in North America, and only second worldwide, in terms of ticket sales for concert events and family shows during the first half of 2005. And ticket sales for sporting events are no less impressive, with the Lightning often playing to sellout crowds of 21,000 or more for regular and post-season home games.

Despite an impressive architectural design and calendar of events, the facility’s P.A. system was felt to be sorely lacking in intelligibility, frequency range and ‘punch’. Consequently, Jason Dixon, SPTF director of broadcasting and programming, and Michael Cooley, arena A-1 engineer, began the search for a new rig by inviting various vendors to come in and demo systems for the room.

This search soon led them to contact the US office of L-ACOUSTICS. Ironically enough, L-ACOUSTICS’ US Sales Manager Dan Palmer is an avid hockey fan and player, and out of a ‘labor of love’ for the sport had previously generated a unique NHL arena design template utilizing the manufacturer’s compact yet powerful dV-DOSC enclosure.

Based on what Palmer had observed in many hockey arena designs, creating another typical exploded cluster type system using spherical sources was not an option, and not something that L-ACOUSTICS would endorse for a number of reasons. Palmer saw the opportunity to provide a concert level system capable of SPL, coverage pattern accuracy, low frequency control and a sight-line friendly profile that would work in tandem with IMAG on the Jumbotron above center ice. This would not be a typical sporting venue P.A. but, rather, a true multiuse sound system for world-class entertainment.

Palmer imported CAD drawings of the Forum into L-ACOUSTICS’ acoustical prediction software, SOUNDVISION, and began to fine-tune his original idea to best suit the space. According to Palmer, “It was only by modeling the system for St. Pete Times Forum in detail that we could look at various design options and ensure that coverage, acoustic accuracy, low frequency control and SPL levels would be acceptable for this installation.

Given that the design focus for the new system is primarily based on the Tampa Bay Lightning’s NHL hockey configuration, dasher boards and glass had to be factored into the equation. The goal, then, was to provide an even blanket of coverage from the first row of seating adjacent to the glass all the way up to the last row in the upper concourse. The system trim height is fixed; the same trim height had to be used for Storm football with no trim or site angle adjustments necessary. Since ice related events specifically request that no direct audio hits the ice surface due to undesirable reflections, it was necessary that the system design take this into account. Another design challenge in any arena is delivering coverage to the corner seating areas (i.e. where the side boards meet the end boards); however, the 120-degree horizontal directivity of dV-DOSC would enable it to provide more than adequate coverage in these otherwise ‘problem’ areas.

Palmer initially looked at distributing the company’s dV-DOSC arrays into six arrays to cover the lower concourse and club levels, and six smaller distributed arrays to cover the upper concourse. However, the system using a dozen arrays was more costly and demanding in terms of installation efforts and time alignment. Furthermore, it did not model as well due to losses in line source coupling at the top of the main lower arrays and bottom of the upper concourse arrays. Specifically, SPL was inconsistent as they lost the -3dB (2x distance) attenuation, a basic factor in line source coupling. With that in mind, Palmer and the L-ACOUSTICS engineering team ultimately chose to ‘keep it simple’ by specifying a system deploying six longer dV-DOSC arrays, each comprised of 11 cabinets positioned below two dV-SUB low frequency enclosures, that would address the entire seating area.

For additional low-frequency reinforcement, twin arrays of four SB218 sub-bass cabinets each would be flown in the geometric center of the three dV-DOSC arrays on each end of the venue. These LF hangs are positioned equidistant from their surrounding MF/HF enclosures and, consequently, the time alignment and distance between subs and each dV-DOSC array is identical. Clearances are within the specification of 70 feet above the ice surface and do not interfere with visual sightlines to the Jumbotron scoreboard above the center ice area.

The DOSC waveguide, an integral component in the design of dV-DOSC, incorporates Wavefront Sculpture Technology® (WST) creating a precision cylindrical wavefront which, according to SOUNDVISION, would focus above the glass to the seating areas with only minor lower frequency spherical energy at ice level yielding outstanding results. The combination of the dV-DOSC/SUB and SB218 enclosures ultimately provided a system capable of SPL with headroom to spare, coverage pattern accuracy, low frequency control, and a sightline-friendly profile.

Additionally, four of L-ACOUSTICS’ ARCS downfill speakers would be positioned on the underside of the scoreboard, added for the benefit of players and performers in need of audio reference on the ice or floor below. When audio reinforcement is not required in this zone, the ARCS downfills could be easily turned off, which would results in greater than 14dB of attenuation in SPL on the ice.

To power all of the loudspeaker elements, L-ACOUSTICS specified that a full complement of its own LA 48a high-efficiency, low-weight power amplifiers be installed in the Forum’s preexisting racks up on the catwalk. Amplifier gain settings are set to strict specifications required by DSP presets to optimize acoustical accuracy and ensure protection of the loudspeaker system. It is important to note that no gain shading or power scaling was used in this system.

Also key to this project was the specification of two wireless Dolby Lake LP4D12 digital signal processors, which would provide unprecedented control of EQ, level of all elements, and, most importantly, zone control of the system.

When the time came to perform the system installation, L-ACOUSTICS turned to the Tampa-based headquarters of Audio Visual Innovations (AVI) – the integration firm that had previously helped demo dV-DOSC for the Forum.

According to Charlie Lawson, AVI’s director of audio, “When looking at a large venue system, predictability is essential. Before we even demoed dV-DOSC for the Forum, I talked with Jason Dixon and Mike Cooley about the advantage of being able to predict P.A. coverage in order to keep the audio out of the broadcast mics on the glass, as well as to achieve the gain-before-feedback required to get ice mics into a P.A. in a large ice arena. I pointed out the difference in the pattern control between L-ACOUSTICS and other manufacturers and made sure they paid close attention to it as the demo systems came through the arena.

“As we walked around and experienced the coverage first hand, they [Dixon and Cooley] were sold. We were able to steer the P.A. coverage above the glass and still hit the first seat, keeping the high end completely out of the broadcast and ice mics, as well as keeping an isolated sound on the ice via the ARCS hung under the score board. It also gave the venue an advantage during other events. Most events take place in the floor with selected coverage either in the seats or on the floor. Now they are able to choose their coverage area more effectively.

“The dV-DOSC cabinet gave us a unique solution in placement of the P.A. as well as coverage. With the wide pattern, very few single arrays were needed and the sight lines turned out to be incredible. As a visitor to the venue, the P.A. is transparent. As an audio engineer visiting the venue, the P.A. performs in ways that exceed our expectations.”

In most arenas, the live audience gets an audio feed that is inferior to the one that is broadcast out to the television viewing audience. However, thanks to dV-DOSC’s exceptional vertical directivity, the potential for feedback has been eliminated, allowing Cooley and his fellow sound engineers to feed broadcast microphones into the house PA. The result is a greatly enhanced experience for the live spectator, who can now hear with startling clarity body checks on the boards and pucks zipping around the glass. In doing so, the St. Pete Times Forum has both changed the way its audience experiences the game and set a new benchmark in bringing this same high definition, high impact sound to its attendees, from the very front row all the way up to the top seats in the house.