COMMERCIAL PAGING AND MUSIC SYSTEMS NBFAA CEU# CARL FOUTZ

PURPOSE OF SOUND SYSTEM n ALLOWS AUDIO SIGNAL TO BE REPRODUCED AT HIGHER LEVEL FOR DISTRIBUTION INTO OTHER AREAS.

TYPES OF SYSTEMS n PAGING – ALERT OR NOTIFICATION n BACKGROUND MUSIC – LOW LEVEL AUDIO FOR "ATMOSPHERE" n FOREGROUND MUSIC – HIGH LEVEL AUDIO FOR "ENTERTAINMENT"

HOW DOES IT WORK? n INPUT DEVICES (MICROPHONE, MUSIC SOURCE) SEND LOW LEVEL SIGNAL TO SIGNAL PROCESSOR n SIGNAL IS PROCESSED (AMPLIFIED, EQUALIZED, MIXED) AND SENT TO OUTPUT DEVICES n OUTPUT DEVICES DISTRIBUTE SIGNAL TO OTHER AREAS AT HIGHER LEVEL

HOW DOES IT WORK? INPUT DEVICES SIGNAL PROCESSOR OUTPUT DEVICES

UNDERSTANDING SOUND LEVELS

WHAT IS A "dB"? n DECIBEL, A RELATIVE MEASUREMENT FOR SOUND PRESSURE LEVEL (LOUDNESS)

TYPICAL dB LEVELS 0 dB 140 dB (THRESHOLD OF HEARING) (THRESHOLD OF PAIN) 10 dB20 dB40 dB60 dB80 dB100 dB120 dB WHISPER CONVERSATION QUIET OFFICE SUPERMARKET DIESEL 50' CONSTRUCTION SITE NOISY OFFICE RESTAURANT

dB AND DISTANCE n EACH TIME DISTANCE FROM SPEAKER IS DOUBLED THE dB LEVEL IS REDUCED BY 3/4X (75%) è LOSS OF 6dB OF POWER n EACH TIME DISTANCE FROM SPEAKER IS HALVED THE dB LEVEL IS INCREASED BY 4X è GAIN OF 6dB OF POWER

DISTANCE EFFECT ON dB 4 FEET 8 FEET 16 FEET 90 dB 84 dB 78 dB

AMPLIFIERS

OHMS VS. WATTS n OHMS – SPEAKERS RATED BY OHM LOAD – SPEAKERS MUST BE BALANCED TO KEEP SYSTEM OHM LOAD CORRECT n WATTS – SPEAKERS ARE RATED BY WATTAGE – IS TOTALED TO DETERMINE AMPLIFIER LOAD – BALANCING LOAD NOT REQUIRED

25V OR 70V SPEAKER LINES? n 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 AWG 18 AWG 16 AWG 5W W W W W

70 VOLT WIRING DISTANCES WIRE GAUGE TOTAL WATTAGE 1W AWG 18 AWG 16 AWG 5W W W W W

SPEAKER WIRING n RUN IN PARALLEL n T-TAPPING IS PERMITTED n 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 n WATTAGE REQUIRED? – SPEAKER LOAD n INPUTS REQUIRED? – MICROPHONE, MUSIC, TELEPHONE n SPECIAL FEATURES – EQUALIZER, TALKBACK, ZONING

MAXIMUM SOUND, MINIMUM SMOKE ALWAYS SIZE THE AMPLIFIER TO THE SPEAKER LOAD, NOT THE SPEAKER LOAD TO THE AMPLIFIER!

CEILING SPEAKER CONSIDERATIONS

SPEAKER PLACEMENT CONSIDERATIONS n AMBIENT (BACKGROUND) NOISE LEVEL n DISTANCE TO TARGET AREA n APPLICATION – PAGING OR BACKGROUND MUSIC

CEILING SPEAKER SPACING n CEILING SPEAKERS SHOULD BE SPACED AT TWO TIMES (2X) THE CEILING HEIGHT – SPEAKER SPACING == CEILING HEIGHT X 2 n 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... n BACKGROUND LEVEL MUSIC/NORMAL PAGING – NORMAL CEILING SPEAKER SPACING (2X) n FOREGROUND LEVEL MUSIC/NOISY AREA PAGING – HALF NORMAL SPACING (1X) – TWICE AS MANY SPEAKERS REQUIRED

SPEAKER MOUNTING n PLENUM CEILING – MAY REQUIRE PLENUM CABLE OR CONDUIT n BACK BOXES – MAY BE REQUIRED ON PLENUM OR PLASTER CEILING n TILE SUPPORT – RECOMMENDED ON DROP CEILINGS

SETTING CEILING SPEAKER WATTAGE BLACK IS COMMON WATTAGE SET BY COLORED WIRES

HORN SPEAKER CONSIDERATIONS

PAGING HORN COVERAGE 30 TO 120 FEET (DEPENDING ON AMBIENT NOISE LEVEL) 40 FEET

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

BOX SPEAKER CONSIDERATIONS

WHEN TO USE BOX SPEAKERS? n MUSIC ONLY OR PAGING WITH MUSIC APPLICATIONS n PROVIDES BETTER QUALITY SOUND FOR MUSIC THAN HORNS n ONLY HALF THE COVERAGE OF HORNS

BOX SPEAKER COVERAGE 15 TO 60 FEET (DEPENDING ON AMBIENT NOISE LEVEL) 20 FEET

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.

SYSTEM WIRING

PAGING AND MUSIC SOURCE WIRING n MICROPHONES – INDIVIDUALLY HOME RUN TO AMPLIFIER – 2C OR 4C (PREFERRED) SHIELDED CABLE n MUSIC SOURCES – INDIVIDUALLY HOME RUN TO AMPLIFIER – 2C SHIELDED CABLE

WIRING AMPLIFIER MICROPHONE BLACK (COMMON) WATTAGE TAP(COLORED) 2C OR 4C SHIELDED MUSIC SOURCE 2C SHIELDED

SPEAKER ZONE PAGING SPEAKER AMPLIFIER ZONE PAGING MODULE PAGING INTO DIFFERENT AREAS (ZONES) BY SWITCHING AMPLIFIER OUTPUT TO DIFFERENT SPEAKERS

AMPLIFIER ZONE PAGING AMPLIFIER #2 SPEAKER AMPLIFIER #1 ZONE PAGING MODULE PAGING INTO DIFFERENT AREAS (ZONES) BY SWITCHING MIC OUTPUT TO DIFFERENT AMPLIFIERS

SPECIAL APPLICATIONS

TELEPHONE PAGING TELEPHONE KSU ISOLATION/MATCHING TRANSFORMER AMPLIFIER AMPLIFIER CONNECTED TO PAGING PORT OR UNUSED C.O. LINE ON THE PHONE SYSTEM SPEAKER

TALKBACK PAGING TELEPHONE KSU C.O. LINE PAGING INTERFACE TALKBACK AMPLIFIER AMPLIFIER CONNECTED TO UNUSED C.O. LINE ON THE PHONE SYSTEM è TALKBACK AMPLIFIER REQUIRED TALKBACK SPEAKER