INTERCOM USING SINGLE REMOTE SPEAKER
Speaker Serves Dual Duty as Microphone and Speaker
This intercom application reduces the hardware requirements for a secure or weatherproof call box like those found in drive‑through talkback systems or secured entryways. The ST‑IC1 Intercom Amplifier input accepts a dynamic mic or phantom powered condenser mic. It can also use an 8 Ω or a 45 Ω speaker as a microphone element. An ST‑LCR1 Logic Controlled Relay is used in this application to switch a remote speaker so that it can function alternately as a speaker and as a microphone.
AMPLIFICATION FOR OUTDOOR POLE-MOUNT SPEAKERS
Pole Mounted Power Amp Operation in Extreme Temperatures
This outdoor parking area is equipped with speakers mounted in the lamp structures to provide music and paging coverage. Speakers in each pole are
powered by an RDL FP‑PA18H 18 Watt Hi‑Temp Audio Amplifier. The amplifier module is mounted in an unventilated watertight enclosure at the base of
each pole. The poles recieve direct sunlight causing the potential for high internal ambient air temperatures.
The highly efficient FP‑PA18H is ideally suited to this environment. It is designed for operation in ambient temperatures up to 70 degrees Celsius (about
158 degrees Fahrenheit) and contributes negligible heat to the ambient temperature inside the pole.
The amplifier’s integral compressor/limiter insures maximum intelligibility by keeping average power levels high and preventing clipping. The FP‑PA18H
combines RDL's high audio performance standards with the capability of operation in harsh temperature environments.
1] If it is desired to monitor the operation of the complete system, the audio detector included in each FP‑PA18H can be wired back to the system audio rack to confirm that audio is being
received and amplified at each pole.
2] If the FP‑PA18H is acquired with an RDL power supply, that supply must be located in an ambient environment not to exceed 40 degress C. FP‑PA18H modules are available without a
power supply for use with high temperature supplies or in systems using distributed 24 Vdc power. Contact RDL Technical Support for more information.
POWERING MULTIPLE STICK-ONS FROM SINGLE SUPPLY
Distributed dc Power From Current-Limited Switching Power Supply
The low current consumption of STICK‑ON modules allows multiple modules to be powered from a single supply. The ST‑PD5U distributes power from any RDL current‑limited switching power supply to up to five modules with a total current requirement of 2 amperes or less. RDL 24 Vdc switching power supplies (purchased separately) are available with current ratings of 500 mA, 1 A and 2 A. All meet ENERGY STAR Level V standards.
TABLE-TOP PRESENTATION PERSONAL MONITOR SYSTEM
Automatic Attenuation Avoids Feedback Between Pick-Up Mic and Monitor Speaker
This sound system is designed to provide clear communication between two presenters and an assembled group. The two presenter positions are each equipped with a table‑top microphone and loudspeaker. The loudspeakers allow the presenters to clearly hear questions from the audience as well as each other. The audience microphone and the two presenter microphones are mixed in the rack; a line‑level signal feeds the amplifiers for the house and the table‑top loudspeakers. Each RDL ST‑GSP1 Gated Speech Preamplifier provides an automatically‑switched line‑level output from a microphone. When an ST‑GSP1 preamplifier is gated ON, the SLAVE (open‑collector) output mutes its associated ST‑MA2 Monitor Amplifier (and RU‑SP1 Monitor Speaker) and attenuates the adjacent monitor speaker, thereby preventing feedback. (Terminals on the ST‑MA2 can MUTE or provide 3 dB or 6 dB of attenuation while pulled to ground, permitting this wiring method to be expanded to multiple presenter stations.)
PAGING IN A MEETING ROOM WITH TWO SOURCES
Paging Connected to a Remote Controlled Mixer with Twisted-Pair Input Modules
The meeting room has two microphone inputs connected to an RDL FP‑TPX3A 2‑input mixer using twisted‑pair cable. Volume for each microphone
is user‑adjusted on the wall‑mounted D‑RC2M which is also connected to the mixer using twisted‑pair cable.
The third input of the FP‑TPX3A is used as the balanced, line‑level paging input. The paging level is set at the mixer so it cannot be turned down
or off by a user in the meeting room.
The FP‑TPX3A allows user remote control of the local inputs while maintaining a fixed level for the facility priority paging. The use of standard
twisted pair cabling using RJ45 connectors cuts both installation time and cost.
SOURCEFLEX SYSTEM FOR DENTAL CHAIRS
Distributed Audio For Dental Offices
Patients select the audio source and listening level in the dental chair using an SAS‑HC8 Headphone Control Station. Three sources are available for selection in each dental chair location: CD player music, Satellite music or MP3 music. The SourceFlex system accommodates a maximum of 8 possible audio sources, plus one paging input. The stereo audio sources are converted to mono using RDL TX‑J2 modules and connected to the rack‑mounted SAS‑8i Audio Input Chassis. All control, power and audio signals connect through a single wiring cable between each SAS‑HC8 and the SAS‑8i. The SAS‑8i supports a maximum of four separate dental chairs and provides connection of multiple expansion chassis: SAS‑82 Two Station Controllers and SAS‑8C Eight Station Controllers. There is no practical limit to the number of possible zones.
Constant Voltage Distributed System
The constant voltage speaker system makes it easy to distribute audio throughout a facility. Speakers can be placed above the listeners tapped for appropriate power levels totalling up to the total amplifier capacity. The TX‑J2 is used to provide a balanced mono signal from the projector’s unbalanced stereo output. For this conference room, the FP‑PA20A constant‑voltage (70 or 100 Volt) amplifier provides up to 20 Watts RMS to speakers located directly above the seating area. The integral compressor/limiter allows high average power levels of audio free from clipping and distortion. The FP‑PA20A can be used in applications that previously would have required amplifiers rated for much higher power levels.
In this example, the amplifier is feeding four speakers at equal power levels. The 70 Volt system makes it easy to distribute audio so that clear, intelligible audio is available for all listeners.
POWERING MULTIPLE SYSTEMS FROM ONE SUPPLY
Remote ON/OFF Control Allows Users to Turn Systems On and Off
The four separate sound systems are comprised of modules in the Equipment Rack powered by a single 24 Vdc power supply. Good engineering practice requires that the power wiring to each component originate at the power supply output. In this installation, the TX‑PD8X Switching Power Supply Distributor serves as the power source for the eight modules comprising the four systems. The TX‑PD8X is equipped with remote control terminals that provide for turning its eight outputs on or off. The wall‑mounted D‑RT2 Remote Control Selector allows users to control the TX‑PD8X, thereby turning the four systems on or off. Visual indication of the ON/OFF status is provided on the remote control. The TX‑PD8X is capable of distributing up to 2 Amps of 24 Vdc power to a maximum of eight dc power jacks from the corresponding RDL current‑limited switching power supply. A smaller RDL power supply may be used for systems with less total module current.
INTERCOM USING DECORA®-STYLE LOUDSPEAKERS
Remote Decora Loudspeakers Serve Dual Duty as Microphone and Speaker
Two RDL D‑SP1A Decora‑style wall‑mounted loudspeakers are used in this intercom system. The control station uses the speaker for monitoring. The remote station uses the D‑SP1A as both microphone and speaker, switched by an RDL ST‑LCR1 Logic Controlled Relay. Signal amplification and muting is provided by a pair of RDL ST‑IC1 Intercom Amplifiers. The D‑SP1A simplifies the physical installation and provides superior audio clarity to similarly‑sized loudspeakers. The control station is equipped with a push‑to‑talk microphone to control the direction of the conversation.
BASIC TWO ROOM COMBINING SYSTEM
School Cafetorium Room Combining System with Automatic Audio Leveling Compression
This cafetorium can be used as one large room or as two smaller rooms formed by movable wall partitions. Each room has one mic and one mono or stereo line‑level input connection through a DS‑J3 input plate. EZ‑MCP1 Microphone Compressors provide consistent level and overload protection on the mic inputs. ST‑CL2 Compressor/Limiters provide the same benefits for the line inputs. The DS‑RCX2 Room Controls provide volume control in each room and allow selection of a common external source (typically background music). The RCX‑5C controls the audio system configuration, separating or combining the inputs and amplified audio to the speakers according to the room usage (one large room or two smaller rooms). The paging input overrides the audio in the entire cafetorium. Note: The RCX‑5C can be used for room combinations from two to five rooms. An HD‑PA35UA Audio Power Amplifier is used for each zone in this system to feed 70 Volt speakers. The HD‑PA35UA has an automatic sleep mode that shuts off the power amplifier when it is not in use. This offers significant energy savings for systems not operated by technical staff.
CLINIC CLASSROOM AUDIO/PAGING SYSTEM
School Paging Interrupts Classroom Audio
This system uses a TX‑PCR1 Paging Controlled Relay to interrupt classroom audio to allow a page to be heard clearly. Classroom audio is fed through a wall plate to the 70 Volt amplifier. The 70 V speaker ouput is routed through normally closed contacts of the paging controlled relay to the clasroom speakers. The paging controlled relay samples the 70 V audio to the classroom paging speaker. Whenever school‑wide paging is active the relay is energized and the classroom audio is interrupted. This allows the page to be heard without interference from the classroom audio. The wall plate used in this example is available in the normal RDL grey/white or in stainless steel with custom labeling available.
PAGING DISTRIBUTION IN LARGE OFFICE COMPLEX
Zoned Paging for Multi-Story Office Building
Installed UTP (unshielded CAT5, CAT6 or similar) cable is used to distribute facility‑wide paging to multiple floors or zones. The three paging sources for this multiple story building are fed to the RDL TX‑TPS3A Active Three Pair Sender. Its RJ45 output is fed to a twisted pair receiver on one floor, then in turn to additional receivers on the other two floors. By setting each TX‑TPR1A receiver to a different receive pair (A, B or C) each floor receives its own paging source. An All Call initiated at the main paging station will page all floors simultaneously. All connections use UTP terminated with RJ45 plugs. A TX‑TPR1A Active Single Pair Receiver on each floor delivers line‑level paging audio to the local amplifier. Each Format A twisted pair receiver bridges the UTP cable, allowing the source signal to continue on to multiple receivers. The receivers are powered from the TX‑TPS3A sender. (Note: If the total distances between the receivers exceeds the recommended cable length for the cable type used, one or more additional power supplies may be required. If needed, an additional power supply may be connected to any of the receiver modules. Consult the Format‑A twisted pair data, or RDL technical support for more information.)
DISTRIBUTED AUDIO FOR MASSAGE PARLOR
SourceFlex System Provides Individual Room Source Selection and Volume Control
The SourceFlex audio system provides individual audio source selection and volume control in each area. An external power amplifier powers the speakers in the larger waiting room. The massage room speakers are powered by room amplifiers built in to the SourceFlex Decora‑style wall controls. Three sources are shown connected to the SAS‑8i rackmounted controller (CD player, Satellite receiver, MP3 player) which accommodates up to 8 selectable sources plus a paging input. Stereo sources are converted to mono using RDL TX‑J2 modules. A paging microphone is preamplified using an RDL STM‑1 to feed the SAS‑8i line‑level paging input.
Clients select the source and set the volume on a D‑SFRC8 wall control with integrated 3.5 W RMS power amplifier. The receptionist selects the source and adjusts the volume in the larger lobby area. A D‑SFRC8L wall control is used to choose the audio source. It provides a line‑level output to an external RDL RU‑PA40D audio amplifier with integral VCA. An RDL D‑RLC10 rotary encoder‑type VCA control adjusts the lobby audio level. The reception station is equipped with a push‑to‑talk button used to page all the listening areas. The SAS‑8i Controller powers up to 4 listening stations, and provides connections to multiple SAS‑8C 8‑station expansion chassis. There is no practical limit to the number of possible listening zones.
4 x 1 STEREO AUDIO SWITCHING IN A CLASSROOM
Remote Source Selection and Volume Control
The classroom is equipped with three A/V sources (Computer, DVD and VCR) and an audio‑only input on a wall plate. Staff selects the audio source and sets the level through the RDL RU‑ASX4DR Remote Controlled Audio Selector using a D‑RC4M Four Channel Remote Control and a D‑RLC10M Remote Level Control. All video signals are run directly to the projector which provides video source selection. Sources may be muted by simply de‑selecting the active input at the D‑RC4M or by operating the MUTE switch on the D‑RLC10M. The D‑CIJ3D Consumer Input Jack Panel is used to balance the stereo signal of an MP3 player or any consumer source and to provide galvanic isolation.
OBSERVATION ROOM AUDIO MONITOR
Loudspeaker or Headphone Listening Station for Microphones Positioned in An Observation Room
Two microphones positioned in the observation room are preamplified and mixed by the ST‑MX2 audio mixer. The line‑level output of the mixer is amplified by the D‑HPA3 3.5 watt power amplifier to feed a wall‑mounted loudspeaker. The D‑HPA3 includes a separate headphone amplifier. The speaker amplifier is set (rear‑panel switch) to mute the speakers when headphones are connected. The front‑panel volume knob controls both the power amplifier and the headphone amplifier level. The high‑impedance bridging input on the D‑HPA3 allows the audio output of the mixer to also feed a recording device.
DISTRIBUTED VGA VIDEO TO MULTIPLE MONITORS
Hotel Provides Multiple Video Monitors that Display Daily Schedule of Events
The daily Calendar of Events listing at this hotel is generated from an office computer. An RDL EZ‑VM14 distributes the VGA signal of the
schedule display to three monitors located near the entrances of the hotel meeting rooms. The wide bandwidth of the EZ‑VM14 insures that the
same high resolution image seen at the local monitor is seen at each hotel monitor.
SEQUENCE LOW VOLTAGE DC POWER AND AMPLIFIERS
Eliminate Audio Pops During System Power-Up and Power-Down
The RU‑SQ6A Sequencing Controller provides complete power distribution management in this sound system. Sequencing the power ON and OFF of the system avoids annoying and sometimes damaging thumps and pops by turning power amplifiers ON last and OFF first. In systems using large power amplifiers, the sequencing of power can also avoid high inrush currents during power up. The RU‑SQ6A features outputs for six sequential steps. The Timing Interval between steps may be adjusted between 1 and 10 seconds. Each step is provided with both Open Collector and SPST dry contact outputs. In this application Open Collector outputs are used to activate the TX‑PD8X Switching Power Supply Distributors that power numerous other RDL products while dry contact closures are used to activate OEM low voltage controllable mains power outlets. Remote ON/OFF control of the RU‑SQ6A is provided by a D‑RT2 Remote Control Selector. Visual indication of the ON/OFF status is provided on the remote control.
OBSERVATION ROOM DOCUMENTATION RECORDING
Two P48 Condenser Microphones Mixed to a Single Recording Channel
The two microphones in the Observation Room are mixed by an ST‑MX2 to a single MIC input on the recorder. The ST‑MPA48 provides phantom power to the two P48 condenser microphones. The ST‑MX2 provides individually selectable MIC or LINE inputs and offers both a MIC and LINE output. Inputs and outputs may each be configured balanced or unbalanced. The ST‑MPA48 provides 48 Vdc phantom voltage for P48 designated condenser microphones. The ST‑MPA48 is normally powered from a standard RDL 24 Vdc power supply or may be powered by any dc voltage from 10.5 volts to 26 volts.
AUDIO SOURCE SELECTION & LEVEL CONTROL
Multiple Control Locations in a Multi-Purpose Meeting Room / Auditorium
The multi‑purpose room is provided with four different line‑level audio sources. Users of the room are able to select their desired source and adjust the audio level from within the space. The RU‑ASX4DR Remote Controlled Audio Selector with VCA is controlled by two D‑RC4M Four Channel Remote Controls (source selectors) and two D‑RLC10 Remote Level Controls (0 to 10 Vdc). Two control locations are shown; up to ten remote locations are possible. All sources may be muted by de‑selecting the active input on either D‑RC4M. The D‑CIJ3D Consumer Interface Jack Panel is used for connection of a user‑supplied audio source.
MULTI-POINT ROTARY ENCODER LEVEL CONTROL
Multiple Control Points for Room or Zone Audio Level with Supervisor Mute Control
In this office sound system, the audio level in the employee work area may be adjusted from two different locations in the area and by the supervisor. Two D‑RLC10 wall‑mounted Remote Level Controls provide rotary volume adjustment and visual indication of the level adjustment in the work area. The supervisor’s D‑RLC10M Remote Level Control with Muting is further equipped with a front‑panel mute button which cannot be overridden by the work area controls. When active, the D‑RLC10M MUTE function shuts off the audio signal. When MUTE is toggled off, audio is restored to the previously set level. The single D‑RLC10M and two D‑RLC10s are shown controlling an RDL ST‑VCA3, or they may be used with any RDL VCA or OEM product requiring a 0 to 10 Vdc Ramp to control level.
NETWORKED AUDIO - ADDING NEW CHANNELS
BGM and Paging Audio Transmitted Between Buildings Over Existing Network
Dante™ networked audio is ideal for audio systems with large channel counts and is equally beneficial in much smaller systems. Cost savings can result from utilizing Dante to transport one to four channels of audio over an existing Local Area Network which would otherwise require the installation of dedicated audio cable between buildings in a school, hospital, church, office complex or factory. This diagram shows background music and a paging microphone sent via Format‑A directly to a local Mixer‑Amplifier in the main building. The Format‑A cabling also sends these sources to the RU‑FNP Format‑A to Network Interface which converts the two sources to two Dante network channels. The signals travel through the network to the satellite building(s) where they are converted back to audio by the FP‑NML2 Network to Mic/Line Interface to feed the BGM and Paging inputs of a Mixer‑Amplifier.
AUDIO EQUALIZATION ENHANCES VOICE INTELLIGIBILITY
AUDIO EQUALIZATION ENHANCES VOICE INTELLIGIBILITY
The ST‑EQ3 3 Band Equalizer shown in this paging system tailors the system for voice‑band intelligibility. The midrange control boosts the voice band (200 Hz to 7 kHz). Low and High band controls attenuate audio frequencies outside of the voice band. The center frequency of each of the three bands may be adjusted by +/‑ 12 dB. Note: The ST‑EQ3 is a cost‑effective module to enhance a variety of systems including adjustable “loudness” equalization for music in PA applications.
Meeting Room Audio using a Centralized Processor
In this facility, all meeting room audio inputs and outputs are networked with a centralized processor to avoid the cost and logistical issues of
installing processors in each room. A single run of CATx cable looped between the three wall‑mounted Format‑A input modules and the RU‑FN Format‑A to Dante Interface module is the only installed cabling required for audio inputs in this meeting room. The line‑level output of a wireless microphone receiver is fed to the Aux Input of the network interface. The Format‑A input modules are powered from the RU‑FN.
MULTIPLE USER LEVEL CONTROLS FOR SINGLE ZONE
Multiple Control Points Provided by Rotary Optical Encoder Remote Controls with Muting
This basic sound system provides two D‑RLC10M Remote Level Controls with Muting for end users to adjust the volume from two different locations. The master D‑RLC10M creates the 0 to 10 Vdc control voltage that sets the gain of the ST‑VCA3 Voltage Controlled Amplifier. The ST‑VCA3 adjusts the audio level feeding the system audio power amplifier. The slave D‑RLC10M sends up/down and muting commands to the master D‑RLC10M. An end user can turn the volume up or down, and mute or unmute the system from either remote control. Pressing the MUTE button on either D‑RLC10M shuts off the audio signal. Audio is restored to the previously‑set level when the MUTE function is released by pressing either MUTE button again.
These controls, one set to MASTER and the other to SLAVE, are shown connected to an ST‑VCA3 Voltage Controlled Amplifier but can be used with any other RDL VCA or OEM product requiring a 0 to 10 Vdc ramp for level control. As many as ten D‑RLC10M Remote Controls may be connected together in one zone. These remote controls are also available in black (DB‑RLC10M) and stainless steel (DS‑RLC10M).
Automatic Ducking with Multiple Paging Locations
This application provides multiple paging locations, with priority assigned to each location. Each location has a mic equipped with a PTT (push‑to‑talk) momentary pushbutton. The STM‑2 preamp for each microphone should be installed near the associated mic. Wiring between each STM‑2 output and the corresponding ST‑VP2 is balanced, connected with shielded or unshielded twisted‑pair cable. When any microphone is used, the music fades down and paging becomes active. The highest priority mic overrides the lower priority mic(s). This arrangement may be carried out for an unlimited number of paging locations.
The FP‑PA20A 20 Watt Power Amplifier feeding 70 Volt speakers is used in this example. RDL offers a wide range of power amplifiers for paging and public address applications.
GATED MIC PREAMPLIFIER DETECTS SIGNAL PRESENCE
Preamp Suppresses Ambient Noise While Idle and Provides Visual Indication of Speech Activity
The ST‑GSP1 Gated‑Speech Preamplifier produces gated line‑level audio from a balanced dynamic or condenser microphone. The preamp output remains off when no one is speaking into the microphone, thereby not picking up and amplifying ambient room noise. The moment someone speaks into the microphone, the output of the ST‑GSP1 turns on, feeding line‑level audio to the sound system. The SLAVE output terminal is used to activate the ST‑LCR1 Logic Controlled Relay which provides a contact closure to turn on a visual indicator. The indicator lamp confirms to the person speaking that the microphone is active. Additional contacts on the ST‑LCR1 are available to turn on other indicators or recording devices. The ST‑GSP1 detection threshold is adjustable. Muting occurs 2 seconds after the audio level drops below the preset threshold. In circumstances where a longer delay time is desired, an external capacitor may be connected to extend the delay. The ST‑GSP1 line‑level output may be configured balanced or unbalanced to feed a variety of audio inputs.
FORMAT-A SOURCE SELECTOR & IN-WALL AMPLIFIER
Distribute Three Audio Sources to Multiple Locations Over UTP Cable
Three styles of music are distributed to various rooms in this facility over CAT 5 cable by an RU‑TPS4A Format‑A Active Sender / Distributor. A D Series‑TPRX3A Source Selector and D Series‑PA3 Audio Amplifier installed in each room allow the occupants to listen to any of the three types of music provided or to listen to their own program material simply by plugging their MP3 player into the front‑panel input on the D‑PA3 amplifier. The front‑panel local input overrides the distributed audio.
PAGING DISTRIBUTION IN OFFICE COMPLEX
Common Paging for Multi-Story Office Building
Installed UTP (unshielded CAT5, CAT6 or similar) cable can be used to distribute facility‑wide paging to multiple floors or zones. The facility paging source for this multiple story building is fed to the RDL TX‑TPS1A Active Single Pair Sender. Its output is fed to a twisted pair receiver on one floor, then in turn to additional receivers on the other floors. All connections use UTP terminated with RJ45 plugs. A TX‑TPR1A Active Single Pair Receiver on each floor delivers line‑level paging audio to the local amplifier. Each Format A twisted pair receiver bridges the UTP cable, allowing the source signal to continue on to multiple receivers. The receivers are powered from the TX‑TPS1A sender. (Note: If the total distances between the receivers exceeds the recommended cable length for the cable type used, one or more additional power supplies may be required. If needed, an additional power supply may be connected to any of the receiver modules. Consult the Format‑A twisted pair data, or RDL technical support for more information.)
SOURCEFLEX SYSTEM - Two Zones
Two Chair Dental Office
The expandable SourceFlex audio system provides distribution of up to 8 audio sources to multiple locations (or zones) throughout a facility.
Source selection and audio level for each zone are controlled by the SAS‑RC8.
In this system, two sources are being distributed to two different patient rooms in a dental office. The stereo outputs from two separate audio
sources (satellite receiver & MP3 player) are converted to balanced mono signals using two RDL TX‑J2s. The mono source signals are fed into
the inputs of the SourceFlex Audio Input Chassis (SAS‑8i). Each room in the dental office has a wall control station (SAS‑RC8), which also
provides power for a local speaker. Only one cable run is needed between each control station and the SAS‑8i Audio Input Chassis for control
and electrical power.
OBSERVATION ROOM DOCUMENTATION RECORDING
Two Condenser Microphones Mixed to a Single Recording Channel
In this Observation Room, an ST‑MX2 mixes the two microphones to a single MIC input on a recorder. The ST‑MPA2 provides phantom power to the two condenser microphones. The ST‑MX2 provides individually selectable MIC or LINE inputs and offers both a MIC and LINE output. Inputs and outputs may each be configured balanced or unbalanced. The ST‑MPA2 can provide phantom voltage for most currently produced condenser microphones when used with a standard RDL power supply.
AUDIO DISTRIBUTION OVER TWISTED PAIR
Multi-Zone Paging w/BGM and Message Repeater
An RDL FP‑MR2 Message Repeater plays back pre‑recorded messages and provides ducking or muting of the BGM source during message playback. The
message repeater can be programmed to repeat automatically or may be triggered manually. Two dynamic or condenser microphones are pre‑amplified to
line‑level by an RDL HR‑MP2 Dual Microphone Preamplifier. All three audio sources (BGM/Message Repeater, Paging Mic 1, Paging Mic 2) are distributed
to each of the three floors of an office or retail building over readily available CAT5 cabling utilizing an RDL RU‑TPS4A Active Sender/Distributor and three
TX‑TPR3A Active Receivers (one per floor). Each Active Receiver provides line‑level audio to an RDL HD‑MA35A Mixer Amplifier. The BGM/Message
Repeater signal connects to Input 2 of the mixer amplifier on each floor. Input 1 of each mixer amplifier is fed from the Receiver output that corresponds
with the Paging Mic (1 or 2) that will be used to page on that floor. Input 1 is set to "duck" the other amplifier input(s) so paging will take priority.
The RDL Format‑A twisted pair products provide flexibility and expandability for this multi‑zone paging system. Additional floors may be added using
additional receiving modules and amplifiers./
TWO ZONE PAGING SYSTEM
Remote Switch at Paging Station Controls Solid-State Audio Routing to Proper Paging Zone
The operator of the paging station can selectively page in either zone. The STM‑2X Switchable Low Noise Microphone Preamplifier amplifies the paging mic to line level. The preamp output is active only while the operator presses the mic push‑to‑talk button. The ST‑RX2 Audio Routing Switcher routes the line‑level audio signal to one of the two amplifiers. The NORMAL output feeds the Zone 1 amplifier; the SELECT output feeds Zone 2. The Audio Routing Switch at the operator’s station controls the ST‑RX2 TRIG terminal. When the ST‑RX2 TRIG control terminal is not connected to ground, audio is fed to the NORMAL output and the SELECT output is turned off. When the TRIG control terminal is grounded, the input audio is routed to the SELECT output and the NORMAL output is muted.
FORMAT-A SOURCE SELECTOR & IN-WALL AMPLIFIER
Distribute Three Audio Sources to Multiple Locations Over UTP Cable
Three styles of music are distributed to various rooms in this facility over CAT 5 cable by an RU‑TPS4A Format‑A Active Sender / Distributor. A D Series‑TPRX3A Source Selector, D Series‑PA3 Audio Amplifier and D SERIES‑SP1A 8 Ohm loudspeaker installed in each room allow the occupants to listen to any of the three types of music provided or to listen to their own program material simply by plugging their MP3 player into the front‑panel input on the D‑PA3 amplifier. The front‑panel local input overrides the distributed audio. The D‑SP1A loudspeaker provides rich detailed sound in a compact Decora compatible format.
OBSERVATION ROOM AUDIO MONITOR
Loudspeaker or Headphone Listening Station for Microphones Positioned in An Observation Room
Two microphones positioned in the observation room are preamplified and mixed by the ST‑MX2 audio mixer. The line‑level output of the mixer is amplified by the D‑HPA3 3.5 watt power amplifier to feed a D‑SP1A Decora‑Style loudspeaker. The D‑HPA3 includes a separate headphone amplifier. The speaker amplifier is set (rear‑panel switch) to mute the speakers when headphones are connected. The front‑panel volume knob controls both the power amplifier and the headphone amplifier level. The high‑impedance bridging input on the D‑HPA3 allows the audio output of the mixer to also feed a recording device.
FIXED MIXING OF PODIUM MIC AND LINE INPUTS
Mixing a Condenser Microphone and Stereo Source to a Mono Line
The sound system in this room is equipped with a mono balanced input from the floor box. When the podium is in use, the presenter uses the condenser microphone and also uses an audio player (or laptop computer) in the podium. The ST‑MPA48 provides the P48 phantom voltage for the condenser microphone. The three inputs on the ST‑UMX3 Universal Audio Mixer mix the microphone with the left and right unbalanced audio player outputs. The ST‑UMX3 provides a balanced mono mic‑level or line‑level (switch‑selectable) feed to the sound system input. The small size of the ST‑UMX3 and the ST‑MPA48 allows them to be installed in the podium or the floor box. The ST‑UMX3 3X1 Universal Audio Mixer is used to combine signals of different level, impedance or balanced/unbalanced configuration. Each input and the output is switch‑selectable for mic or line level. Single‑turn trimmers are provided for the gain adjustment of each input. The ST‑MPA48 contains two identical phantom power circuits and a common power supply input. If only one mic input is to be converted for phantom operation, only one circuit needs to be used. Phantom voltage is not present on the output terminals.
Intercom System for Health Care Facility
This intercom system allows a health care worker to communicate with a patient in the adjacent room while keeping both hands free for taking notes, using a computer, or accessing reference material. This system is set up with two intercom amplifiers that are both switchable by the health care worker. A foot switch provides a dry contract to control the directional flow of the audio. The ST‑IC1 intercom amplifiers can provide phantom power to condenser microphones and will directly drive a low impedance speaker.
SEND UNBALANCED AUDIO OVER A LONG DISTANCE
Balanced Audio Connections Between Stereo Unbalanced Devices
Unbalanced audio is not suited to long distance transmission due to susceptibility to hum and ground loops. This problem is avoided by balancing the audio source prior to transmission and by isolating the received signals with effective common mode (hum) rejection. This application uses an RDL STA‑2A Dual Line Amplifier to boost the unbalanced stereo source up to the standard +4 dBu level to drive a pair of balanced lines. The balanced lines may be shielded or unshielded (UTP) and may be up to several hundred feet long. An RDL TX‑A2D Dual Audio Converter receives the balanced audio, converts it to unbalanced and attenuates it to a standard ‑10 dBV level feeding RCA output jacks. Studio quality audio transformers in the TX‑A2D provide very high common‑mode hum rejection and galvanic isolation from the balanced lines. The received remote source is connected to one of the stereo unbalanced inputs of an RDL EZ‑MX4L stereo audio mixer that feeds the conference room amplifiers and speakers.
MEDICAL OFFICE DISTRIBUTED SOUND SYSTEM
Facility-wide Background Music with Examination Room Paging
This medical office is set up as a two zone system in which only the examination rooms receive paging. All rooms in the facility are provided
with background music.
The HD‑MA35UA Mixer Amplifier (Zone 1) powers the speakers in multiple examination rooms where paging is required. Its Zone 2 mixer output
provides balanced line‑level background music without paging to the FP‑PA35A Power Amplifier that powers the speakers in the reception and
waiting room. Two wall‑mounted AMS‑10K controls permit independent volume adjustment for each zone. The HD‑MA35UA features an integral
VCA for Zone 1 level control. An ST‑VCA3 is used to control the level in the areas served by the FP‑PA35A. The ST‑VCA3 is powered by the
auxiliary module 24 Vdc power output from the HD‑MA35UA.
Note: If the waiting room is small enough for background music supplied by one or two low‑power speakers, the system may be installed without the FP‑PA35A, ST‑VCA3 and associated AMS‑10K,
instead using the HD‑MA35UA Zone 2 amplifier (4 W) to power low impedance speakers in the waiting room.
The HD‑MA35UA and FP‑PA35A both enter an automatic sleep mode to provide significant energy and cost savings when the system is idle.
KSU/PBX PAGING WITH BGM OVERRIDE
Paging System for Office Space with BGM Override
This example shows how to utilize a telephone line (input) port on an existing KSU to add paging from the telephone system to a background music (BGM) system. The ST‑TC1 acts as a virtual telephone line when connected to a KSU FX port. When that “line” is selected using any phone instrument connected to the KSU, the ST‑TC1 provides audio from the instrument mouthpiece to the ST‑VP2 Automatic Ducking Module. The ST‑VP2 automatically ducks the background music audio for the duration of the page, then ramps up the music at the end of the page. In this example an FP‑PA20A 70 volt amplifier is powering 70 volt loudspeakers in the office area. The ST‑TC1 provides relay contact closures when it is activated by a telephone instrument. The relay contacts can be used to provide additional functions when paging is active, including visual indicators or triggering a radio transmitter.
Quality Audio System for Boardroom or Conference Room
Many projectors incorporate source switching and audio level adjustment into their remote controls. They seldom offer a high quality audio power amplifier suitable for a large boardroom or conference room. The TX‑PA40D fills that need. A stereo amplifier with integral compressor/limiter, the TX‑PA40D is capable of maintaining high average audio power levels free from clipping and distortion. There is an input switch to sum the stereo inputs for those facilities where speaker placement does not allow for good stereo imaging.
In this example, the amplifier is feeding two pairs of 8 Ohm speakers so that four speakers can be used to evenly distribute the audio throughout the room. The compact footprint of the TX‑PA40D allows it to be mounted to the projector or other convenient location. This compact, professional amplifier may be mounted in just a few square inches of space.
NETWORKED AUDIO PAGING
Multiple Paging Zones
A Dante™ network is used to distribute several sources of facility‑wide paging to multiple buildings. Within each building (one is shown),
networked audio is converted to RDL Format‑A for distribution to three floors using an RU‑NFD Network to Format‑A Interface/Distributor. Each
paging source is routed to Format‑A Pair A, Pair B or Pair C through Dante Controller. The RU‑NFD provides three Format‑A output jacks that
each send audio on pairs A, B & C to a twisted pair receiver on one floor, then in turn to additional receivers on the other two floors. By setting each TX‑TPR1A receiver to a different receive pair (A, B or C), each floor receives its own paging source. An All Call initiated at the main paging station will page all floors simultaneously. All connections use UTP terminated with RJ45 plugs. A TX‑TPR1A Active Single‑Pair Receiver on each floor delivers line‑level paging audio to the local amplifier. Each Format A twisted pair receiver bridges the UTP cable, allowing the source signal to continue on to multiple receivers. The receivers are powered from the RU‑NFD. (Note: If the total distances between the receivers exceeds the recommended cable length for the cable type used, one or more additional power supplies may be required. If needed, an additional power supply may be connected to any of the receiver modules. Consult the Format‑A twisted pair data, or RDL technical support for more