AV Technology - March 2008 - (Page 51)

BOUNDARY EFFECTS Low-frequency loudspeakers or subwoofers that operate below 125 Hz can often be installed or located in a way that allows it to increase its total output. A rigid surface acts as an “acoustic mirror,” with each surface “reflecting” up to an additional 6 dB of gain at low frequencies. So a subwoofer placed in a floorwall corner could produce up to 18 dB more output than if it were suspended from the ceiling in the middle of the room. It seems like magic, but it’s not really. When an LF loudspeaker (which radiates it energy omnidirectionally) is located close to a rigid boundary, the boundary is simply capturing and re-directing the energy that would otherwise continue to radiate if the boundary wasn’t there. The key is that it must be a truly rigid boundary; a concrete wall or floor works best. A less rigid boundary can either pass the LF energy or be “actuated” by it, thus dissipating it rather than re-directing it. —Mark Mayfield Touch comes to Listen Don’t miss a single sound. MCDONALDS IN TEXAS • Ideal for boardrooms, universities, courtrooms, council meetings, and government conferences touchscreen • Software for control, voting, polling, video display, and web streaming • Stand-alone “plug & play” • Uses Cat-5e cabling • Intuitive and easy to use productive the ceiling and walls then act to increase low-end performance by pushing more of the low frequency energy into the room.” [See sidebar, “Boundary Effects.”] Beyond the main dining area—referred to as “the lobby” in McDonald’s parlance—Argabright’s audio blueprint extended into a children’s play area, the previously mentioned room adjacent to the main dining area (which is used for everything from employee training to private parties), and even outdoors. Performing collectively within a single zone configuration across all of these areas of coverage, the system uses a pair of QSC’s surface-mount AcousticDesign AD-S52T loudspeakers for sound reinforcement within the children’s area and four additional surface-mount loudspeakers (AcousticDesign model AD-S32T) outdoors at the entrance to the restaurant. Complementing the audio segment of the AV system, display elements spread throughout the restaurant include a pair of 52-inch Sharp Aquos LCD screens in the lobby, a pair of 47-inch model 1080p LCD screens from LG in the children’s area, and a single 42-inch LG model 720p LCD screen in the smaller area adjacent to the lobby. Distribution for the screens is all via Cat-5 cabling; an Intelix splitter distributes video program material arriving on-site from four Dish network receivers. The entire AV systems integration project was completed in November of 2007. Since that time, both the audio and video improvements have been received very well. With David Argabright proudly noting that the system sounds better than any other quick service restaurant he can think of, Jeff Weller reports that he plans on introducing similar designs to other McDonald’s within the R.E.E. franchise realm as renovations spread to other locations. INFO INTELIX: www.intelix.com LG ELECTRONICS: www.llge.com QSC AUDIO: www.qscaudio.com SHARP: www.sharpusa.com Touch and hear for yourself Free no obligation demonstration +1.800.330.0891 North America or +1.801.233.8992 sales@listentech.com • www.listentech.com Gregory A. DeTogne is a freelance writer who lives and works in Libertyville, IL. He can be reached at greg@detogne.net. march 2008 | AVTECHNOLOGY | 51 assistive listening • • tour group • language interpretation • conferencing http://www.intelix.com http://www.llge.com http://www.qscaudio.com http://www.listentech.com http://www.sharpusa.com http://www.listentech.com

Table of Contents Feed for the Digital Edition of AV Technology - March 2008

AV Technology - March 2008 Contents Precedent Corporate: Whose Job Is It Anyway? Education: There’s No Business Like Show Business Government: Technology and the New World Order Buying a Videoconference System They Will Actually Use AV After Hours The Sound of HD Conferencing Assembling the Design Team Concert Hall Acoustics on a High School Budget Audio Architecture Keeping a Watchful Eye Product Spotlight Tech Horizons Product Review New Products AV MO

AV Technology - March 2008

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