The famed blue turf at Albertsons Stadium at Boise State University in Idaho – the first school to feature a non-green field – is a distinctive feature of the school’s Broncos football program. Another distinctive feature of the venue is a powerful L-Acoustics K2 system that delivers crystal-clear sound to every corner of the stadium from a compact installation. Salt Lake City-based Poll Sound worked closely with the L-Acoustics Applications team to engineer the solution to fit within the existing video board structure, launching the system just in time for the 2024-2025 college football season.
“It’s a typical college stadium in terms of its design and architecture,” says Poll Sound AV System Designer and Project Engineer Bryce Stettler. “However, the video board that had been installed the year prior had wings designed and pre-installed for the sound, and the main challenge we faced was designing and installing the best possible sound system within those pre-existing spaces. We had great components from L-Acoustics, in the form of the K2 and Kara II loudspeakers, and great assistance from L-Acoustics’ own experts and Soundvision software. Together, we could make all the pieces of this puzzle fit perfectly.”
The new system is a left-right design consisting of four arrays of seven K2 per array and two arrays of nine Kara II, plus eight KS28 subs flown four per side. Fill sound below the scoreboard is handled by four arrays of three A15i mounted to the underside, with three more arrays of three A10i addressing a corner seating area that’s shaded from the scoreboard. Distributed delay under-balcony sound is addressed with 27 A10i Wide speakers lining the length of both sides of the stadium. Main and fill speakers are powered by 15 LA7.16i amplified controllers, with two LA12X for the subs – all in four separate amp racks in different locations. The systems are managed by a P1 processor and connected via ten LS10 Avnu-certified AVB network switches to streamline the audio distribution across the rack locations.
“The spaces on either side of the scoreboard were very tight, maybe ten feet high in three separate sections, so we were pretty confined in terms of how much space we could use for the main arrays,” explains Neil Yates, Poll Sound’s Manager of Engineering. “In most of our stadium designs we prefer a much larger line array because you’ve got a lot more height available, which allows more control to lower frequencies. Whereas, in this scoreboard, each array could be a maximum of ten feet high because of how the scoreboard was built. But we still had to meet the requirements for speech intelligibility and throw. It was challenging.”
Stettler says that the assistance from L-Acoustics was critical and forthcoming. “They helped enormously with the design, and we relied heavily on Soundvision,” he says. “The software was key in making sure that the coverage was going to work, that the intelligibility would be there, that we would have coverage where it needed to be, and that the distances would be fully covered. Kara II was a great solution for the upper bowl areas, which helped us get coverage of the sound much further out in the upper bowl with no loss of intelligibility or frequency range. But it was really the K2 that were the workhorses of this project. They can really get the sound where we need it to be. It was the right tool for the job, and we’ve been really impressed with how well it works for the long-throw distances because of the power in that box and its ability to maintain it across long distances.”
Yates adds that the match between the K2 and KS28 subs also contributes to giving fans in the stands a full-range sonic picture of the game, a soundtrack of music, and announcers that complement the action on the field. In fact, the system achieved a STIPA (Speech Transmission Index for Public Address Systems) rating of 0.8. “It’s an excellent intelligibility rating, but as far as music and playback, that’s where the K2 has really shined. It has added a lot of full range and plenty of power, as well, for impact.”
The new sound system has transformed the game-day experience both inside and outside the stadium. “What we’ve achieved here is remarkable,” says Nathan Burk, Senior Associate Athletic Director of Operations & Governance at Boise State University’s Department of Athletics. “Our previous system required extremely high-volume levels to reach every seat, which created an uncomfortable listening experience and affected our campus neighbors. Now, we have crystal-clear sound that immerses fans in the game experience while being more considerate of our downtown location. Everyone inside the stadium can clearly understand announcements and enjoy the atmosphere, regardless of where they’re seated, and we’re achieving this with more precise audio control than ever before.”
Stettler says the sound system’s performance is that much more of an achievement given the space constraints the scoreboard design imposed on it. “It was all about fitting everything together but without compromising anything,” he says. “Everything looks great and sounds great. L-Acoustics really made that happen.”
For more info on Albertsons Stadium, visit www.broncosports.com/facilities. Poll Sound can be found online at www.pollsound.com.
