Vol. 3, No. 10 Shure Brothers Incorporated

222 Hartrey AvenueEvanston, IL 60202-3696(847) 866-2200

Scott Air Force Base, locatedin southern Illinois, is the head-quarters for the Air MobilityCommand and the U.S. Trans-portation Command. Both com-mands are involved with complexmilitary logistics, i.e., how tomove troops, equipment, andsupplies.

Located within Scott AFB isthe Global Reach Planning

Center (GRPC). GRPC containsan auditorium used for trainingand planning conferences thathouses the largest one-roomAMS system in the world.Consisting of 160 AMS chan-nels, the system provides soundreinforcement within the audito-rium. Communitronics, based inSt. Louis, Missouri, designedand installed the total audio/

video/control network.The auditorium has eight lev-

els, each of which has three longrectangular tables and associ-ated chairs. Each seat locationis equipped with an AMS24 thatis mounted via an A24QG. TheA24QG mates with a recessedfemale Neutrik XLR connector.A plastic cover plate hides this

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Scott AFB 's GRPC auditorium featuring 160 AMS channels

SCOTT AFB -‘A”M’s’s9~~:N”‘T~~‘~Continued from Page 1

Scott AFB Global Reach Planning Center (GRPC)

connection point. Each seatlocation also has a Local AreaNetwork connection for laptopcomputers.

The AMS mics are divided intoten zones, with 16 mics perzone. Located above each zoneare ceiling mounted loudspeak-ers that look like 2’ x 2’ whiteceiling tiles. The loudspeakersare divided into eight zones.Each loudspeaker zone has adedicated power amplifier and adigitally controlled analog equal-izer. This type of equalizer waschosen as the settings are donevia a computer link and cannotbe changed once the control

computer is disconnected.The ten AMS mic zones feed

into 20 AMS8000 mixers andfour AMS4000 mixers. Thesemixers are configured to provideten unique zone outputs. Theseten zone outputs are fed into apair of Meridian Communi -cations DistraMix devices, an 8In to 8 Out matrix mixer For thissite, two DistraMix devices werelinked to provide a 16 In to 8 Outsignal path. The DistraMix out-puts feed the equalizers.

With this system configura-tion, each loudspeaker zonegets a unique mix of the tenAMS mic zones. This type of sys-

AMS24 mic shown with mounting equipment, including A24QG,Neutrik XLR connector, and plastic cover plate

GRPC AMS mixer complement

tern is known as Mix Minus, i.e.,each ceiling loudspeaker zonereceives a complete mix minusthe AMS mics located directlybelow. A Mix Minus designincreases gain before feedbackdramatically as the mics closestto any loudspeaker do not

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AMS24 mic mounted via A24QG

2

AMS KNOWS THE WAY TO

San Jose City council chambers

Frequent readers of theUpdate know the AMS is apopular choice for city councilsystems. The San Jose CityCouncil Chambers recentlyjoined the long list of AMScounci l si tes. Specif ied byLewi tz and Assoc ia tes o fSausalito, California, the sys-tem was installed by RiverviewSystems Group, a San Jose-based company.

Three AMS8000 mixers anda single AMS4000 are linkedfor a total of 28 inputs. Micro-phone styles employed areAMS24 goosenecks, AMS26probes and AMS28 lavaliers.

As is typical in legislative audiosystems, the AMS logic capabili-ties were put to work. Use of theMute In function not only pro-vides individual privacy switchesfor each council member, but

also allows the mayor and cityclerk to deactivate the audiencemicrophone when necessary.The Gate Out function is utilizedto mute local overhead loud-speakers whenever a daismicrophone activates. The GateOut also controls a “Mic On”indicator lamp at each mem-ber’s location. (See the AMSInstaller’s Manual for these logiccircuits.)

In addition to the AMS, aShure LS24 wireless micro-phone is available for presenta-tions and Shure FP16A distribu-tion amplifiers provide recording

and media feeds. Other audioequipment includes a Whiteequalizer, a Crown power ampli-fier, Soundolier loudspeakers, aTascam recorder, and a PhonicEar assistive listening system.

Robert Scharffer, senior con-

3

COUNCILMEMBER’S CONTROL PANEL CONCEPT gp_NTS

CONTROL PANEL INSTALLATION CONCEPT o_NTS

San Jose City control panel and installation detail

SAN JOSE

Council member position

sultant at Lewitz and Associates,remarks, “When designing acouncil sound system or similargovernment facility, the AMS isthe only way to go. The loud-speaker muting logic circuitry(when using the dais micro-phones) worked wonderfully. Wewere able to increase the sys-tem gain before feedback. Also,the options provided by the AMSwere similar to features in theprevious system. Since we wereable to recreate familiar func-tions with new technology, theusers’ transition to the new sys-tem was fairly seamless, andcouncil members were verypleased with the new unclut-tered look of the dais.”

A tip of the hat to RobertScharffer for kindly sending thephotos and information used inthis story.

Council chambers equipment rack

SCOTT AFB - THE LARGEST ONE-ROOM AMS SITE IN THE WORLDContinued from Page2

appear in that loudspeaker The tor ium. Acoustic gain (thefinal matrix mix was not a true increase in audio level with theMix Minus as it was decided to system “on” versus systemfeed a little of each mic zone into “off”) averaged about 10dBthe nearest loudspeaker zone. with the talker 12 inches fromThis “sidetone” reassures the the mic. Ambient noise in thetalker that he is being heard in auditorium was a very accept-the sound system. able 43dB SPL A weighted.

After the final three-hour The AMS directional gatingtune-up to the Mix Minus was essential to the successmatrix, a person talking into of the system. Without AMSany AMS24 could be easily directional gating , overheadheard throughout the audi- loudspeakers and paper shuf-

AMS PUMPS UPTHE MINNESOTAIRON RANGE

Virginia, Minnesota lies inthe heart of Minnesota’s ironmining range. Recently, thesound system in the councilchambers was upgraded byNortech Communications ofHibbing, Minnesota. Havingheard from other city councilsthat the Shure AMS worksextremely well in legislative set-tings, Nortech called Shure foradvice on using the AMS for acity council.

The final design has 13 chan-nels of AMS. The microphoness e l e c t e d i n c l u d e A M S 2 6probes and AMS28 lavaliers. AShure LS24/87 wireless isalso used for presentations andaudience questions.

The AMS audio output servesmult iple purposes. One issound reinforcement in thechambers, which was accom-plished with an Edcor poweramplifier and Valcom loud-speakers. Another is assistivel i s t en ing f o r t he hea r i ngimpaired, for which a WilliamsSound system was employed.

In addition, press feeds aresupplied by the AMS via a ShureFP16A distribution amplifier.Like many other city councils inthe United States, the Virginia

fling would randomly activatemics throughout the room.This site is an excellent exam-ple of how the AMS directionalgating is the best choice undercertain circumstances.A world of thanks to Mike

Leitensdorfer and the crew atCommunitronics for the back-ground i n fo rma t i on andsuperb photos documentingtheir innovative AMS designand installation.

Virginia, Minnesota city council chambers

council broadcasts its meetingson local cable television. Thecable audio feed is taken fromthe FP16A. Citizens can phonein questions to the city througha Telos 100 telephone intercon-n e c t - a device often used forradio talk shows.

According to Nortech, “TheAMS is a wonderful system towork with and we received greattechnical support from Shure.We feel that the AMS is thebest automatic system for confer-ence room sound reinforce-ment. The Virginia council statesthat the AMS provides the bestsound they have ever had. Nowpeople watching the city councilmeetings on TV can hearclearly, as well as can any hear-ing-impaired audience memberin the council chambers.”

Aw shucks, folks, we’re blush-

ing. Our thanks to SheilaKvilvang of Nortech Commu-nications who provided thephotos and information for thisstory.

Back Issues ofAMS Update Available

If you missed previous issues ofAMS Update, theby contacting Max B

may be obtaineduchanan at Shure

and requesting the issues you want.If in Europe, you can contact:SHURE GmbHWannenacker Str. 2874078 HeilbronnGermany$l;fon: 49-7131-72140

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