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COMMERCIAL PAGING AND MUSIC SYSTEMS. NBFAA CEU # 96-0344 CARL FOUTZ. PURPOSE OF SOUND SYSTEM. ALLOWS AUDIO SIGNAL TO BE REPRODUCED AT HIGHER LEVEL FOR DISTRIBUTION INTO OTHER AREAS. TYPES OF SYSTEMS. PAGING ALERT OR NOTIFICATION BACKGROUND MUSIC LOW LEVEL AUDIO FOR "ATMOSPHERE"
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COMMERCIAL PAGING AND MUSIC SYSTEMS NBFAA CEU# 96-0344 CARL FOUTZ
PURPOSE OF SOUND SYSTEM • ALLOWS AUDIO SIGNAL TO BE REPRODUCED AT HIGHER LEVEL FOR DISTRIBUTION INTO OTHER AREAS.
TYPES OF SYSTEMS • PAGING • ALERT OR NOTIFICATION • BACKGROUND MUSIC • LOW LEVEL AUDIO FOR "ATMOSPHERE" • FOREGROUND MUSIC • HIGH LEVEL AUDIO FOR "ENTERTAINMENT"
HOW DOES IT WORK? • INPUT DEVICES (MICROPHONE, MUSIC SOURCE) SEND LOW LEVEL SIGNAL TO SIGNAL PROCESSOR • SIGNAL IS PROCESSED (AMPLIFIED, EQUALIZED, MIXED) AND SENT TO OUTPUT DEVICES • OUTPUT DEVICES DISTRIBUTE SIGNAL TO OTHER AREAS AT HIGHER LEVEL
HOW DOES IT WORK? SIGNAL PROCESSOR INPUT DEVICES OUTPUT DEVICES
UNDERSTANDING SOUND LEVELS
WHAT IS A "dB"? • DECIBEL, A RELATIVE MEASUREMENT FOR SOUND PRESSURE LEVEL (LOUDNESS)
TYPICAL dB LEVELS RESTAURANT NOISY OFFICE SUPERMARKET QUIET OFFICE DIESEL TRUCK @ 50' WHISPER CONVERSATION CONSTRUCTION SITE 10 dB 20 dB 40 dB 60 dB 80 dB 100 dB 120 dB (THRESHOLD OF HEARING) 140 dB 0 dB (THRESHOLD OF PAIN)
dB AND DISTANCE • EACH TIME DISTANCE FROM SPEAKER IS DOUBLED THE dB LEVEL IS REDUCED BY 3/4X (75%) • LOSS OF 6dB OF POWER • EACH TIME DISTANCE FROM SPEAKER IS HALVED THE dB LEVEL IS INCREASED BY 4X • GAIN OF 6dB OF POWER
DISTANCE EFFECT ON dB 4 FEET 8 FEET 16 FEET 90 dB 84 dB 78 dB
OHMS VS. WATTS • OHMS • SPEAKERS RATED BY OHM LOAD • SPEAKERS MUST BE BALANCED TO KEEP SYSTEM OHM LOAD CORRECT • WATTS • SPEAKERS ARE RATED BY WATTAGE • IS TOTALED TO DETERMINE AMPLIFIER LOAD • BALANCING LOAD NOT REQUIRED
25V OR 70V SPEAKER LINES? • COMMERCIAL PAGING/MUSIC SPEAKERS RUN ON 25V OR 70V SPEAKER CIRCUITS • 70V CAN RUN 8 TIMES THE DISTANCE OF 25V ON THE SAME GAUGE WIRE
25 VOLT WIRING DISTANCES WIRE GAUGE TOTAL WATTAGE 1W 1000 5000 8000 5W 300 1000 1800 10W 200 500 800 25W 70 300 200 50W 40 100 150 100W 15 50 70 22 AWG 18 AWG 16 AWG
70 VOLT WIRING DISTANCES WIRE GAUGE TOTAL WATTAGE 10W 2000 5000 7000 25W 600 1800 2500 50W 400 800 2500 100W 150 400 700 1W 10000 12000 14000 5W 3000 7000 12000 22 AWG 18 AWG 16 AWG
SPEAKER WIRING • RUN IN PARALLEL • T-TAPPING IS PERMITTED • KEEP BLACK (COMMON) AND WATTAGE TAP (COLORED) WIRE ON SAME CONDUCTOR THROUGHOUT
SUGGESTED SPEAKER LOAD ALLOWANCES AMBIENT NOISE LEVEL CEILING HORN/BOX QUIET (50-70dB) 1/2 TO 1 WATT 1 TO 5 WATT NOISY (74-85dB) 1 TO 2 WATT 5 TO 10 WATT VERY NOISY (86-96dB) 2 TO 4 WATT 10 TO 15 WATT
RELATIONSHIP BETWEEN AMP POWER & SOUND PRESSURE • 2 WATTS = + 3DB • 4 WATTS = + 6DB • 10WATTS= +10DB (TWICE AS LOUD AS 1 WATT) • 20WATTS = +13DB • 40WATTS = +16DB • 100WATTS= +20DB (FOUR TIMES AS LOUD AS 1 WATT) • 200WATTS= +23DB • 400WATTS= +26DB • 1000WATTS=+30DB (EIGHT TIMES AS LOUD AS 1 WATT)
DISTANCE EFFECT ON dB 4 FEET 8 FEET 16 FEET 90 dB 84 dB 78 dB
AMPLIFIER SELECTION CONSIDERATIONS • WATTAGE REQUIRED? • SPEAKER LOAD • INPUTS REQUIRED? • MICROPHONE, MUSIC, TELEPHONE • SPECIAL FEATURES • EQUALIZER, TALKBACK, ZONING
MAXIMUM SOUND, MINIMUM SMOKE ALWAYS SIZE THE AMPLIFIER TO THE SPEAKER LOAD, NOT THE SPEAKER LOAD TO THE AMPLIFIER!
SPEAKER PLACEMENT CONSIDERATIONS • AMBIENT (BACKGROUND) NOISE LEVEL • DISTANCE TO TARGET AREA • APPLICATION • PAGING OR BACKGROUND MUSIC
CEILING SPEAKER SPACING • CEILING SPEAKERS SHOULD BE SPACED AT TWO TIMES (2X) THE CEILING HEIGHT • SPEAKER SPACING == CEILING HEIGHT X 2 • SPACED EQUAL TO CEILING HEIGHT (1X) FROM WALLS
SPEAKER SPACING-TOP VIEW 1X CEILING HEIGHT 2X CEILING HEIGHT
SPEAKER SPACING-SIDE VIEW 2X CEILING HEIGHT CEILING HEIGHT
ON CEILING SPEAKERS... • BACKGROUND LEVEL MUSIC/NORMAL PAGING • NORMAL CEILING SPEAKER SPACING (2X) • FOREGROUND LEVEL MUSIC/NOISY AREA PAGING • HALF NORMAL SPACING (1X) • TWICE AS MANY SPEAKERS REQUIRED
SPEAKER MOUNTING • PLENUM CEILING • MAY REQUIRE PLENUM CABLE OR CONDUIT • BACK BOXES • MAY BE REQUIRED ON PLENUM OR PLASTER CEILING • TILE SUPPORT • RECOMMENDED ON DROP CEILINGS
SETTING CEILING SPEAKER WATTAGE BLACK IS COMMON WATTAGE SET BY COLORED WIRES
PAGING HORN COVERAGE 40 FEET 30 TO 120 FEET (DEPENDING ON AMBIENT NOISE LEVEL)
HORN FORWARD PROJECTION AMBIENT SQUARE FT. NOISE LEVEL PROJECTION COVERAGE QUIET (50-70dB) 120 FEET 5000 S.F. NOISY (74-85dB) 60 FEET 2500 S.F.VERY NOISY (86-96dB) 30 FEET 1250 S.F.
DISTANCE EFFECT ON dB 4 FEET 8 FEET 16 FEET 90 dB 84 dB 78 dB
STAGGERED PATTERN ALL HORNS FACING SAME DIRECTION
OPPOSITE PATTERN HORNS FACING OPPOSITE DIRECTION NO OTHER HORNS FACING INTO THESE
IMPROPER HORN LOCATION NEVER! CAUSES CANCELLATION AND DECREASED INTELLIGIBILITY!
SETTING HORN/BOX SPEAKER WATTAGE WATTAGE TAP SET BY ROTATING SWITCH OR SETTING DIP SWITCHES
WHEN TO USE BOX SPEAKERS? • MUSIC ONLY OR PAGING WITH MUSIC APPLICATIONS • PROVIDES BETTER QUALITY SOUND FOR MUSIC THAN HORNS • ONLY HALF THE COVERAGE OF HORNS
BOX SPEAKER COVERAGE 20 FEET 15 TO 60 FEET (DEPENDING ON AMBIENT NOISE LEVEL)
BOX FORWARD PROJECTION AMBIENT SQUARE FT. NOISE LEVEL PROJECTION COVERAGE QUIET (50-70dB) 60 FEET 2500 S.F. NOISY (74-85dB) 30 FEET 1250 S.F.VERY NOISY (86-96dB) 15 FEET 625 S.F.
PAGING AND MUSIC SOURCE WIRING • MICROPHONES • INDIVIDUALLY HOME RUN TO AMPLIFIER • 2C OR 4C (PREFERRED) SHIELDED CABLE • MUSIC SOURCES • INDIVIDUALLY HOME RUN TO AMPLIFIER • 2C SHIELDED CABLE
BLACK (COMMON) WIRING 2C OR 4C SHIELDED AMPLIFIER MICROPHONE 2C SHIELDED MUSIC SOURCE WATTAGE TAP(COLORED)
SPEAKER ZONE PAGING ZONE PAGING MODULE SPEAKER AMPLIFIER SPEAKER PAGING INTO DIFFERENT AREAS (ZONES) BY SWITCHING AMPLIFIER OUTPUT TO DIFFERENT SPEAKERS
AMPLIFIER ZONE PAGING AMPLIFIER #1 ZONE PAGING MODULE SPEAKER AMPLIFIER #2 SPEAKER PAGING INTO DIFFERENT AREAS (ZONES) BY SWITCHING MIC OUTPUT TO DIFFERENT AMPLIFIERS
SPECIAL APPLICATIONS
TELEPHONE PAGING TELEPHONE KSU AMPLIFIER SPEAKER ISOLATION/MATCHING TRANSFORMER AMPLIFIER CONNECTED TO PAGING PORT OR UNUSED C.O. LINE ON THE PHONE SYSTEM
TALKBACK PAGING TELEPHONE KSU TALKBACK AMPLIFIER TALKBACK SPEAKER C.O. LINE PAGING INTERFACE AMPLIFIER CONNECTED TO UNUSED C.O. LINE ON THE PHONE SYSTEM • TALKBACK AMPLIFIER REQUIRED