NOISE MASKING
Two-Zone Noise Masking System for Office Space
AN-2039
Description:
This application shows the layout of a two zone noise masking system. The white noise line output from the RDL ST‑NG1 feeds the inputs of two RDL FP‑PEQ3 parametric equalizers. The FP‑PEQ3 equalizers allow the installer to flatten the noise spectrum in each zone. The line output of each FP‑PEQ3 is fed through RDL FP‑PA20A 20W, 70/100 V power amplifiers. The 70 V output of each FP‑PA20A feeds multiple 70 V speakers in its associated zone. Multiple equalizers and amplifiers may be added for larger systems with more zones.
MULTI-POINT ROTARY ENCODER LEVEL CONTROL
Multiple Control Points for Room or Zone Audio Level with Supervisor Mute Control
AN-2171
Description:
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.
LINE LEVEL MEDIA FEED DISTRIBUTION
Buffering High Quality Audio Feeds
AN-2141
Description:
Speeches, government meetings, product announcements and other media events covered by reporters require multiple high quality audio feeds
in the press room. The recording equipment may require a balanced or unbalanced line level or mic‑level signal. Each output feed must be
isolated so that if one output is accidentally shorted or back‑fed, all other feeds and the public address system remain unaffected. An RDL
RU‑ADA8D Audio Distribution Amplifier provides isolated audio output signals that drive a variety of audio jacks on a "Media Panel." An RDL
RU‑MX4 Professional 4‑Input Mixer with selectable compressor is used to mix the audio sources. The line‑level mix is distributed by the
RU‑ADA8D to up to 16 line‑level outputs on RCA, 1/4" phone, or XLR jacks. Any of these outputs could be padded down to mic level using RDL
TX‑LM2 line‑level to microphone‑level transformers. All jacks shown are on Decora® compatible wall plates. These jacks are also available in
the RDL AMS series should a custom rack or tabletop configuration be preferred. Video distribution may be added using RDL composite and
VGA/XGA distribution amplifiers.
FORMAT-A SOURCE SELECTOR & IN-WALL AMPLIFIER
Distribute Three Audio Sources to Multiple Locations Over UTP Cable
AN-2220
Description:
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.
RF SUPPRESSION IN AUDIO OR CONTROL CIRCUITS
RFI Suppressed on Six Signal Conductors
AN-2177
Description:
The ST‑FS6 Ferrite Suppressor / RF Filter is used to attenuate excessive RF interference (RFI) induced in the wiring conductors by a nearby communications tower. The passive ST‑FS6 provides six isolated channels of highly effective ferrite RF suppression without capacitance to ground or series resistance. Two ground terminals are provided to be used as tie points for connecting cable shields (not pictured). The ground lugs have no internal connection to the suppression circuitry. Each of the six I/O terminals may be used independently for the suppression of RF on Audio, dc power or logic control signal conductors. RF interference on audio and control wiring causes unwanted audio noise or instability in control circuits. The ST‑FS6 is normally installed at the rack where signals are received. It is possible that interference may interfere with audio or control sending equipment, making it beneficial to install a suppressor module at both ends of the long interconnection lines.
ELIMINATE AUDIO AND VIDEO HUM IN MEETING ROOM
Galvanic Isolation for Audio and Composite Video “Ground Loopsâ€
AN-2098
Description:
Picture and sound quality from the player on the equipment cart is easily degraded by a “ground loopâ€. The difference in ground voltage between the audio/video source and monitoring locations can create herringbone patterns or rolling hum bars in
the video, and hum in the audio. Small “ground loop†voltages can easily impair the quality of audio and/or video signals. The RDL EZ‑HK3 removes the “ground loop†using a stereo pair of high quality audio and video transformers in a shielded metal enclosure. The input jacks are ground‑isolated. A ground‑lift switch allows the output jack shields to be lifted from the metal chassis if required.
OFFICE AUDIO SYSTEM FOR ENHANCED PRODUCTIVITY
Employee-Selectable Private (Headphone) or Public (Speaker) Monitoring of Two Office Sources
AN-2170
Description:
Each office is equipped with two active stereo audio inputs that may be listened to via the overhead loudspeaker or through headphones. The local computer is connected to one input. The other input is available for a user‑supplied playback device, such as a Personal Media Player used for dictation, recorded meeting playback or music. Software alerts enabled on the computer will be heard along with the Personal Media Player playback because both audio inputs are active at all times. Confidential playback content remains private by turning off the overhead speaker and using the headphones powered by the DS‑HA1A Stereo Headphone Amplifier. Computer or Personal Media Player audio suited or intended to be heard in the whole office may be amplified to an appropriate listening level by the DS‑TPA1A 3.5 W Audio Power Amplifier.
4 x 1 STEREO AUDIO SWITCHING IN A CLASSROOM
Remote Source Selection and Volume Control
AN-2211
Description:
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.
AUTOMATICALLY SWITCHED PODIUM MICROPHONE
Floor Mat Pressure Switch Mutes Microphone when Not in Use
AN-2156
Description:
A podium microphone that is continuously left on can create an annoying “live†reverberant sound in many meeting rooms. This can be distracting before and after meetings and during breaks. This application shuts the microphone off when no one is at the podium, keeping the public address system quiet when no one is speaking. A commercially available floor mat security switch is placed behind the podium under a carpet mat (or under installed carpet for fixed podiums). When the presenter stands on the mat, its contact closure enables the audio output of the STM‑2X Switched Microphone Preamplifier that feeds the public address amplifier and speakers (not shown). Stepping off the mat releases the closure and mutes the microphone. The output of the STM‑2X provides both mic and line‑level outputs that may be wired balanced or unbalanced, making it compatible with any new or existing audio system. An EZ‑MCP1 Microphone Compressor is installed between the microphone and the STM‑2X to provide consistent audio levels from any presenter, and to avoid overloads that could produce distortion and clipping.
BASIC TWO ROOM COMBINING SYSTEM
School Cafetorium Room Combining System with Automatic Audio Leveling Compression
AN-2124
Description:
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.
ADDING A ZONE TO AN EXISTING DISTRIBUTED 70 V SYSTEM
AN-2025
Description:
A 70 V audio signal is being distributed to multiple zones in a facility. The RDL TX‑70A provides for the expansion of the existing 70 V system by converting the 70 V signal to an unbalanced line level signal. The unbalanced audio signal feeds the FP‑PA20A 20 Watt 70 V Audio Power Amplifier, which powers the speakers in the additional zone. The TX‑70A is equipped with a level trimmer for achieving optimal signal level.
DANTE INPUTS AND OUTPUTS IN THE WALL
Meeting Room with Portable Active Loudspeakers
AN-2245
Description:
All audio processing in this meeting room is handled by a centrally‑located Dante‑enabled DSP. The RDL DD‑BN22 Bi‑Directional Mic/Line Dante Interface provides inputs for up to two microphones and analog outputs to feed the two portable active loudspeakers. Each XLR input provides three switches that are set from the front of the unit before the cover plate is installed. One switch enables or disables P48 phantom; the second switch selects the mic or line gain range; the third switch sets the gain. Rear‑panel switches set each XLR output to mic or line level.
POWER 3 ACTIVE SPEAKERS ON FORMAT-A CABLE RUN
Power Inserter / Signal Breakout Module Permits Home Run Cabling From a Dante™ Network
AN-2234
Description:
Each Format‑A active loudspeaker requires 100 mA of supply current. A TX‑TP4PW Power Inserter / Signal Breakout module provides up to 200 mA to each D‑PSP1A active loudspeaker. The TX‑TP4PW Power Inserter / Signal Breakout module is used to receive Pairs A, B and C from a single cable run connected to the RJ45 output of the RU‑BNF Format‑A Bi‑Directional Network Interface. The RU‑BNF converts 3 Dante sources to Format‑A. Those sources on pairs A, B and C are all passed through to each home run cable that connects to the RJ45 input of each D‑PSP1A Format‑A loudspeaker. A rear‑panel switch set during installation selects which of the three audio sources is amplified by the powered speaker. All D‑PSP1A loudspeakers may be set to the same pair if desired. All the Format‑A modules are powered by the external supply connected to the TX‑TP4PW. This setup can be replicated for the remaining two Format‑A outputs from the RU‑BNF. Additionally, the Format‑A input on the RU‑BNF may be used to convert three Format‑A sources onto the Dante network (not shown).
AUDIO INPUTS AND OUTPUTS IN THE PODIUM
Networked with a Centrally-Located DSP
AN-2246
Description:
The RDL DD‑BN2ML Wall‑Mounted Bi‑Directional Mic/Line Dante Interface provides all necessary audio connectivity for this meeting room and is networked with a centrally‑located Dante‑enabled DSP. The XLR input provides three switches that are set from the front of the unit before the cover plate is installed. One switch enables or disables P48 phantom; the second switch selects the mic or line gain range; the third switch sets the gain. The 3.5mm input sums the left and right channels of a stereo source to mono to feed one Dante network transmit channel. The two male XLR connectors on the D‑XLR2M wall plate are wired to the two line level outputs on the rear of the DD‑BN2ML to feed the two active loudspeakers. The DD‑BN2ML and D‑XLRM2 are shown mounted together in a triple‑gang RDL surface‑mounted box.
AUTOMATIC POWERING OF BOARDROOM A/V SYSTEM
Automatically Turn System On and Off to Conserve Energy and Simplify Operation
AN-2103
Description:
The RDL FP‑ECC1 Energy Conservation Controller provides the capability to automatically power up the boardroom A/V electronics when needed and to power down the equipment when not in use to conserve energy and reduce operating costs. FP‑ECC1 “trigger†inputs bridge the mic and line level signals from the room and are used to switch the system on. Then the presence of any speaker‑level signal at the FP‑ECC1 “hold†input keeps the system powered. After a switch‑selectable time period of 15, 30, or 60 minutes of no use, the FP‑ECC1 will turn off the system electronics. No operator intervention is needed to begin or end use of the system. Audio and video inputs from the room are fed through RDL wall plates. The D‑ECR1 Power On/Off Remote Control allows users to manually power up/down the equipment controlled by the FP‑ECC1 Controller. The D‑ECR1 matches the style of the other wall plates.
SEND UNBALANCED AUDIO OVER A LONG DISTANCE
Balanced Audio Connections Between Stereo Unbalanced Devices
AN-2095
Description:
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.
NOISE MASKING WITH PAGING
Constant Voltage System for Noise Masking and Overhead Paging
AN-2136
Description:
Random white noise generated by the ST‑NG1 White and Pink Noise Generator is fed to Input 2 of the HD‑MA35A Mixer Amplifier. A Paging
Source is connected to Input 1 of the HD‑MA35A. The Mixer Amplifier can be programmed to attenuate (duck) the white noise by 25dB
during a paging event. Ducking can be initiated either manually, from a contact closure on the paging device, or automatically by adjusting the
Input 1 VOX sensitivity on the HD‑MA35A. The ST‑NG1 is powered directly from the 24 Vdc output on the rear of the HD‑MA35A.
ELIMINATE AUDIO HUM IN BOARD ROOM OR CONFERENCE ROOM
Galvanic Isolation for Audio “Ground Loopâ€
AN-2099
Description:
A laptop computer that is connected to AC power typically produces a “ground loop†if its audio output is connected to a sound system amplifier. The difference in ground voltage between the computer and amplifier causes a hum in the audio signal. Small “ground loop†voltages can produce high audio hum levels from the speakers. The RDL EZ‑HK1 between the computer and the amplifier removes the “ground loop†using a stereo pair of high quality audio transformers in a
shielded metal enclosure. The input jacks are ground‑isolated. A round‑lift switch allows the output jack shields to be lifted from the metal chassis if required. Audio connections are easy to interface between jack types. The EZ‑HK1 input provides both stereo RCA jacks and a stereo mini‑jack. The output
also is provided on stereo RCA jacks or a stereo mini‑jack.
NETWORKED AUDIO
Meeting Room Audio using a Centralized Processor
AN-2225
Description:
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.
ELIMINATE AUDIO HUM IN A GROUP PRESENTATION
Galvanic Isolation for Stereo Audio Ground Loop or Computer Digital Noise
AN-2084
Description:
Presentations using a laptop computer face problems of delivering quality audio through an unbalanced connection. Any difference in ground
potential between the computer and audio amplifier creates “hum†that becomes part of the presentation audio. In some systems, digital noise
from the computer may also add a constant irritating background noise to the audio.
The RDL AV‑HK1 easily solves this common problem. The AV‑HK1 breaks the ground path for “hum†and ditigal noise using stereo audio
isolation transformers in a rugged, tightly shielded enclosure.
The AV‑HK1 “Hum Killer†is a must‑have item for the touring presenter and is equally useful in a fixed AV installation.
BLUETOOTH WITH ADJACENT LINE INPUTS OVER CATx
Format-A with CATx Cable Adds Separate Analog User Line Inputs to Wireless Bluetooth Source
AN-2250
Description:
One Format‑A receiver is used to provide two mono line‑level signals to a local mixer‑amplifier in the equipment rack. Bluetooth audio is sent to
the receiver on pair B. Pair C is used to receive mono‑summed audio through the Mini‑Jack or pair of RCA jacks mounted next to the Bluetooth
receiver. Audio is connected from the Format‑A senders through CATx cable with standard RJ45 connectors. The use of Format‑A provides
simple connection using CATx cable and the economy of a single receiver and power supply.
MEETING ROOM MIXER WITH NO SETUP REQUIRED
Remote Controlled Mixer Provides User Adjustment in Multi-Purpose Space
AN-2085
Description:
The RDL FP‑TPX3A Remote Controlled Mixer makes setup easy for a wide variety of uses in this hotel meeting space. A visit to the AV closet is
not required when shifting from one use to the next.
The three FP‑TPX3A inputs are fed from any of the Format‑A twisted pair senders. Each Format‑A input module provides one balanced
microphone input. (Line‑level Format‑A input modules are also available.) The three input modules are chained together and connected to the
mixer using standard twisted pair cable with RJ45 connectors. A separate twisted pair cable connects the D‑RC3M Remote Mixing Control to the
mixer. The D‑RC3M provides a separate level control and mute button for each of the three inputs. The wall mounted control is simple to use and
easy to understand even for facility users with no technical background.
The FP‑TPX3A provides a solution for flexible use of multi‑purpose rooms that does not require technically trained staff for setup.
PRIORITIZED PAGING
Paging from Multiple Locations
AN-2016
Description:
This application provides multiple paging locations, with priority assigned to each location. Each location has a mic with a PTT (push‑to‑talk) momentary pushbutton that provides external switching contacts. The STM‑2 preamp for each microphone should be installed near the associated mic. Wiring between each STM‑2 output and the corresponding ST‑LCR1 is balanced, connected with shielded or unshielded twisted‑pair cable. When a PTT button associated with a microphone is depressed, 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. If the background music source provides only unbalanced outputs, an STA‑1M Audio Line Amplifier may be used to provide a balanced signal at the proper level.
If solid state switching is preferred, an ST‑SSR1 Solid State Audio “Relay” may be substituted for each ST‑LCR1.
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.
ELIMINATE AUDIO HUM IN MEETING ROOM OR CLASS ROOM
Galvanic Isolation for Audio “Ground Loopâ€
AN-2096
Description:
A laptop computer that is connected to AC power typically produces a “ground loop†if its audio output is connected to an installed sound system. The difference in ground voltage between the computer and equipment rack amplifier causes a hum in the audio signal. Small “ground loop†voltages can produce high audio hum levels from the speakers. Installing the RDL EZ‑HK1 between the computer and the system input removes the “ground loop†using a stereo pair of high quality audio
transformers in a shielded metal enclosure. The input jacks are ground‑isolated. A ground‑lift switch allows the output jack shields to be lifted from the metal chassis if required. Audio connections are easy to interface between jack types. The EZ‑HK1 input provides both stereo RCA jacks and a stereo mini‑jack. The output also is provided on stereo RCA jacks or a stereo mini‑jack.
POWERING MULTIPLE SYSTEMS FROM ONE SUPPLY
Remote ON/OFF Control Allows Users to Turn Systems On and Off
AN-2172
Description:
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.
TWO ZONE PAGING SYSTEM
Remote Switch at Paging Station Controls Solid-State Audio Routing to Proper Paging Zone
AN-2192
Description:
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.
AUDIO DISTRIBUTION OVER TWISTED PAIR
Multi-Zone Paging w/BGM and Message Repeater
AN-2144
Description:
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./
AMPLIFIERS FOR MEETING ROOM AND OVERFLOW AREA
Conference Facility Audio System with Amplification for Additional Zone
AN-2128
Description:
This conference facility uses the HD‑MA35UA 35 Watt Mixer Amplifier as the main integrated audio solution. Two D‑J1 Decora XLR Wall Plates
feed the microphone inputs on the mixer section of the HD‑MA35UA. An RLC10KM provides a level control for the 70 Volt speakers serving the
main conference room.
The Zone 1 Line Output from the HD‑MA35UA provides audio to the overflow seating area behind the meeting room. An FP‑35A 35 Watt Audio
Amplifier powers the 70 Volt speakers in the expansion section. The audio level in this area is adjusted by an RLC10KM connected to an
ST‑VCA3 Voltage Controlled Amplifier. The ST‑VCA3 is powered by the auxiliary module 24 Vdc power output from the HD‑MA35UA.
The HD‑MA35UA and FP‑PA35A both enter an automatic sleep mode to provide significant energy and cost savings when the system is idle.
USE A CATX HOME RUN FOR EACH FORMAT-A SOURCE
Power Inserter / Signal Breakout Module Permits Home Run Cabling to Dante™ Network
AN-2233
Description:
In this Format‑A installation, it was not practical to loop CATx cable between the senders in different rooms. A home run from each microphone sender was pulled to the equipment rack. The TX‑TP4PW Power Inserter / Signal Breakout module is used to connect Pairs A, B and C to a single cable run and to insert power. The sources sent on pairs A, B and C are all present on the cable that connects the TX‑TP4PW to the RJ45 input of the RU‑FN format‑A to Network Interface. Each of the three sources will be transmitted on a separate Dante channel. All the Format‑A modules are powered by the external supply connected to the TX‑TP4PW.
5.1 SURROUND SOUND REMOTE LEVEL CONTROL
Multi-Channel Level Control for Theater or Control Room
AN-2159
Description:
The RU‑VCA6A Six Channel Digitally Controlled Attenuator and RLC10K Remote Level Control are used to increase and decrease the level of the 5.1 Surround Sound source feeding the amplifiers.
The RU‑VCA6A offers clickless level adjustment, accurate tracking and outstanding wide‑band, low‑noise studio quality performance. It can be controlled remotely by a variety of RDL or third‑party controls and/or locally via front‑panel pushbuttons. Each audio input and output may be configured balanced or unbalanced. Multiple RU‑VCA6As and/or RU‑VCA2As may be linked together for single‑point level control of 7.1, 10.2 or 22.2 surround sound systems.
AUDIO SOURCE SELECTION & LEVEL CONTROL
Multiple Control Locations in a Multi-Purpose Meeting Room / Auditorium
AN-2212
Description:
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.
SEQUENCE LOW VOLTAGE DC POWER AND AMPLIFIERS
Eliminate Audio Pops During System Power-Up and Power-Down
AN-2173
Description:
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.
DANTE NETWORK INPUTS AND OUTPUTS IN THE WALL
Briefing Room Mics and Near-Field Monitors
AN-2247
Description:
All audio processing in this briefing room is handled by a centrally located Dante‑enabled DSP. The RDL DD‑BN2M Bi‑Directional Mic/Line Interface connects the two microphones and the two permanently installed D‑PSP1 Decora‑Style Active Loudspeakers to the Dante network. Each D‑PSP1 serves as a near‑field monitor and is fed from the line‑level outputs on the rear of the DD‑BN2M. Each XLR input provides three switches that are set from the front of the unit before the cover plate is installed. One switch enables or disables P48 phantom; the second switch selects the mic or line gain range; the third switch sets the gain.
POWERING MULTIPLE STICK-ONS FROM SINGLE SUPPLY
Distributed dc Power From Current-Limited Switching Power Supply
AN-2193
Description:
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.
LOCAL ZONE LEVEL CONTROL OF NETWORKED AUDIO
Adapt Standard Audio Amplifiers to a Dante&trade Network
AN-2237
Description:
An FP‑NML2V Network to Mic/Line Interface with VCA receives two channels of Dante networked audio, one for each room or zone. The digital audio is converted to balanced audio to drive any standard amplifier. The FP‑NML2V incorporates a VCA in each audio output. Each VCA is controlled by a D‑RLC10 Remote Level Control in the zone. The D‑RLC10 is a rotary encoder style remote that provides a 0 to 10 Vdc control output. One FP‑PA35A Power Amplifier drives the speakers in each zone. The amplifier gain is fixed at the maximum level needed in the zone. Users adjust the audio level in the zone using the D‑RLC10. Because the level in the zone is adjusted by the FP‑NML2V, any standard audio amplifier may be used for each zone.
PORTABLE AV CART
Networked with a Centrally-Located DSP
AN-2244
Description:
The RDL DD‑BN31 Wall‑Mounted Bi‑Directional Mic/Line Dante Interface provides all necessary audio connectivity for this meeting room and is networked with a centrally‑located Dante‑enabled DSP. Each XLR input provides three switches that are set from the front of the unit before the cover plate is installed. One switch enables or disables P48 phantom; the second switch selects the mic or line gain range; the third switch sets the gain. The 3.5mm Line Input and Line Output can be set independently by the installer for STEREO or MONO operation. Two line‑level analog outputs are provided on the rear‑panel detachable terminal block and are switch selectable for balanced (+4 dBu) or unbalanced (‑10 dBV) operation. The rear‑panel outputs are intended for connection to RDL AMS connectors mounted in Decora‑style plates that match the DD‑BN31. AMS audio connectors include RCA, Mini and XLR jacks.
FORMAT-A SOURCE SELECTOR & IN-WALL AMPLIFIER
Distribute Three Audio Sources to Multiple Locations Over UTP Cable
AN-2224
Description:
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.
ISOLATED MEDIA FEEDS
Buffering Multiple High Quality Audio Feeds
AN-2009
Description:
Speeches, government meetings, product announcements and other media events are occasions where a number of reporters in the electronic press require a high quality audio feed from the event organizers. The recording equipment in use might require a mic, balanced line level or unbalanced line‑level signal. It is critical that each feed is isolated so that if one feed is accidentally shorted or back‑fed, no other feed will be affected nor will the public address system. This example uses RDL STICK‑ONs® to provide isolated audio output signals driving a variety of audio jacks on a "Media Panel." An RDL RU‑MX4 Pro 4‑Input Mixer is used as the audio source. The line‑level source is distributed through an ST‑DA3 Audio Distribution Amplifier to line‑level outputs on RCA, 1/4¨ phone, and XLR jacks. The same source is padded down to mic level using an STP‑1 Attenuator and distributed through an STM‑DA3 Microphone Distribution Amplifier to the mic outputs. All jacks shown are on Decora® wall plates. These jacks are available in the RDL AMS series should a rack or tabletop mount be preferred. Distribution of video at these events can also be added using RDL composite and VGA/XGA distribution amplifiers.
BOARDROOM AUDIO POWER AMPLIFICATION
VCA Controlled Audio Amplifier with Matching Remote Control and Input Connector Plates
AN-2102
Description:
RDL passive input plates are used to connect audio and video from the boardroom to a central equipment rack for processing and recording. The D‑AVMB2 Audio and Video Jack plate is used for a laptop computer; the D‑XLR3F XLR Female Jack plate is used for the lectern microphone. The line output of the audio mixing/switching equipment in the rack feeds an RDL RU‑PA40D Stereo Audio Amplifier. The amplifier is equipped with an internal VCA which is controlled by the RLC10K Remote Level Control that matches the style of the input plates. The RU‑PA40D provides ample compressed audio power to meet the requirements of both small and large boardrooms and conference rooms.
AV SYSTEM FOR CORPORATE FACILITY
Boardroom AV System
AN-2110
Description:
Three compact RDL EZ‑series modules handle all the audio and video signals for both local presentations in this boardroom and to interface with
video conferencing. The EZ‑MX4ML Mic and Stereo Line Audio Mixer and the EZ‑MXA20 20 Watt Stereo Audio Mixer Amplifier together provide
3 mic inputs with phantom power and 3 stereo line‑level inputs. The EZ‑MXA20 provides 10 Watts to each of the 8 Ohm speakers in the room
and allows for bass and treble tone control adjustment. The EZ‑VM22E VGA/XGA Switcher/Equalized Amplifier switches between the video
conference system and the local video source. It also routes the selected video source to both monitors in the room. All the RDL system
electronic products are mounted in an EZ‑CC6 Component Chassis. The EZ‑RA6 Rack Adapter is available for rack mounting of the EZ series
modules.
TWO MIC INPUTS FEED DANTE™ NETWORK OVER CATx
Dual Mic Preamp Provides 48 V Phantom and Automatic Gain Setting
AN-2239
Description:
The D‑TPSM2A Dual Microphone Preamplifier is installed in the meeting room for users to connect one or two wired microphones. The module provides 48 V phantom and is compatible with both dynamic and condenser microphones. Rear panel GAIN switches for each channel are set to AUTO by the installer to automatically provide 60 dB of gain for dynamic mics or 40 dB for condenser mics. The D‑TPSM2A output feeds the preamplified microphone signals to two Format‑A pairs. The output cable loops through a D‑TPSL1A interface which accepts a mono or stereo audio source that it sums to mono. The mono output from the D‑TPSL1A feeds the remaining Format‑A cable pair. The Format‑A cable terminates into an RU‑FN Format‑A to Network Interface module that converts the sources to three Dante network channels. The line‑level output of a wireless microphone receiver is connected to the Aux Input of the RU‑FN to feed its fourth Dante output channel. The Format‑A input modules are both powered from the RU‑FN. A single CATx cable run is the only installed cabling required for audio inputs in this meeting room
COMBINE THREE SOURCES ON ONE FORMAT-A PAIR
Expand the Capacity of a Format-A Cable Run Using a Three-Pair Combiner
AN-2232
Description:
The TX‑TPSA1A Three‑Pair Combiner to Single‑Pair Sender is used to add up to two additional sources to one pair in a Format‑A system. Each of the three D‑TPS1A single‑pair microphone senders is set to feed a unique pair (A, B or C). These senders are daisy chained on one CATx cable run connected to the INPUT of the TX‑TPSA1A combiner where the three pairs are summed to feed Pair A. Two D‑TPSL1A single‑pair senders (set to feed pairs B and C) are looped together on a second cable run connected to the LOOP IN of the combiner. All three pairs are present at the OUTPUT which can be connected to any RDL Format‑A receiver, distributor or compatible Dante interface. DC power connected to the TX‑TPSA1A powers all five senders. Note: Up to three TX‑TPSA1A modules may be daisy chained on one cable run, permitting as many as nine senders to feed audio through a single Format‑A cable (three sources on each pair A, B and C)
STEREO REMOTE AUDIO LEVEL CONTROL
Studio Quality Volume Adjustment for Professional and Consumer Applications
AN-2158
Description:
The RU‑VCA2A Two Channel Digitally Controlled Attenuator and RLC10K Remote Level Control are used to increase and decrease the level of the Stereo Sound source feeding the amplifiers.
The RU‑VCA2A offers clickless level adjustment, accurate tracking and outstanding wide‑band, low‑noise studio quality performance. It can be controlled remotely by a variety of RDL or third‑party controls and/or locally via front‑panel pushbuttons. Each audio input and output may be configured balanced or unbalanced. Multiple RU‑VCA2As and/or RU‑VCA6As may be linked together for single‑point level control of 7.1, 10.2 or 22.2 surround sound systems.
CORPORATE CONFERENCE/PRESENTATION CENTER
Audio/Visual, Wireless Mic System, 3 Channel Mixing with 40 Watt Amplifier
AN-2051
Description:
This Conference/Presentation center is equipped with multiple wall input plates for auxillary audio/video sources such as a laptop computer and wireless microphone. The system includes a mixer with remote volume and muting control. Wall plates are shown at the front of the room where presentations are normally staged. The video input jack is wired directly to the projector using a standard VGA video cable. All signal and control connections between the three wall plates and the mixer use CAT5 wire. The remote controlled mixer is used to set audio levels from the audio input wall plates. The volume and muting controls are located at the front of the room allowing easy access before and during presentations. The amplifier is switched to mono and 4Ω; the output is driving four 8Ω speakers. All wall controls and panels are available in RDL standard white/gray or in stainless steel with custom labeling available.
MIX MIC SOURCES IN A ROOM TO ONE DANTE™ CHANNEL
Expand the Capacity of a Single Dante Channel Using a Format-A Three-Pair Combiner
AN-2231
Description:
The TX‑TPSA1A Three‑Pair Combiner to Single‑Pair Sender is used to add up to two additional sources to one pair in a Format‑A system. Each of the three D‑TPS1A single‑pair microphone senders is set to feed a unique pair (A, B or C). These senders are daisy chained on one CATx cable run connected to the INPUT of the TX‑TPSA1A combiner where the three pairs are summed to feed Pair A. The TX‑TPSA1A output feeds an RDL RU‑FN Format‑A to Dante Interface. Microphones connected to any of the mic‑input senders will be sent on the first Dante output channel. Two D‑TPSL1A single‑pair senders (set to feed pairs B and C) are looped together on a second cable run connected to the LOOP IN of the combiner. These sources will be sent independently on the second and third Dante channels. DC power connected to the TX‑TPSA1A powers all five senders. Note: Up to three TX‑TPSA1A modules may be daisy chained on one cable run, permitting as many as nine senders to feed audio through a single Format‑A cable and to be sent on three Dante network channels.
MULTIPLE USER LEVEL CONTROLS FOR SINGLE ZONE
Multiple Control Points Provided by Rotary Optical Encoder Remote Controls with Muting
AN-2169
Description:
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).
GATED MIC PREAMPLIFIER DETECTS SIGNAL PRESENCE
Preamp Suppresses Ambient Noise While Idle and Provides Visual Indication of Speech Activity
AN-2176
Description:
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.
FIXED MIXING OF PODIUM MIC AND LINE INPUTS
Mixing a Condenser Microphone and Stereo Source to a Mono Line
AN-2202
Description:
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.
PRESENTATION AUDIO
Constant Voltage Distributed System
AN-2069
Description:
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.
USE A CATX HOME RUN FOR EACH FORMAT-A SOURCE
Power Inserter / Signal Breakout Module Permits Home Run Cabling
AN-2236
Description:
In this Format‑A installation, it was not practical to loop CATx cable between the senders in different rooms. A home run from each microphone sender was pulled to the equipment rack. The TX‑TP4PW Power Inserter / Signal Breakout module is used to connect Pairs A, B and C to a single cable run and to insert power. The sources sent on pairs A, B and C are all present on the cable that connects the TX‑TP4PW to the RJ45 input of the TX‑TPR3A Line‑Level Format‑A Receiver. All the Format‑A modules are powered by the external supply connected to the TX‑TP4PW
MEDIA FEED DISTRIBUTION
Buffering Multiple High Quality Audio Feeds
AN-2140
Description:
Speeches, government meetings, product announcements and other media events covered by reporters require multiple high quality audio feeds
in the press room. The recording equipment may require a balanced or unbalanced line level or mic‑level signal. Each output feed must be
isolated so that if one output is accidentally shorted or back‑fed, all other feeds and the public address system remain unaffected. An RDL
RU‑ADA4D Audio Distribution Amplifier provides isolated audio output signals that drive a variety of audio jacks on a "Media Panel." An RDL
RU‑MX4 Professional 4‑Input Mixer with selectable compressor is used to mix the audio sources. The line‑level mix is distributed by the
RU‑ADA4D to up to 8 line‑level outputs on RCA, 1/4" phone, or XLR jacks. Three of its outputs are padded down to mic level using RDL TX‑LM2
line‑level to microphone‑level transformers. All jacks shown are on Decora® compatible wall plates. These jacks are also available in the RDL
AMS series should a custom rack or tabletop configuration be preferred. Video distribution may be added using RDL composite and VGA/XGA
distribution amplifiers.
PRIORITY SWITCHING FROM A VIDEO SOURCE
Multiple Conference Rooms Automatically Switch to a Priority Video Presentation
AN-2006
Description:
This application note shows one of several conference rooms on a corporate campus. The Local A/V Equipment is normally used for meetings held in the room. When a single presentation must be viewed by the entire corporate staff, all the conference rooms are used simultaneously. When the campus‑wide presentation is played, the TX‑AVX module in each conference room detects the video signal, switches off any local video and routes the presentation video to the projector. The TX‑AVX slave output controls the ST‑SSR1 which switches off any local audio and routes the presentation audio to the projector or other audio amplifier used in the room. Two ST‑SSR1 modules may be connected for stereo. Automatic switching insures the presentation will be viewed in every conference room.
AUDIO EQUALIZATION ENHANCES VOICE INTELLIGIBILITY
AUDIO EQUALIZATION ENHANCES VOICE INTELLIGIBILITY
AN-2178
Description:
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.
CONSISTENT LEVELS FROM MEETING ROOM MICS
Automatic Microphone Level Control for Enhanced Intelligibility with Untrained Presenters
AN-2150
Description:
In this meeting room rack, three HR‑MCP2’s are connected between microphone inputs and the system’s DSP based microphone auto‑mixer to
reduce demands on the DSP’s resources while providing consistent levels from each of the system’s six microphone inputs. The HR‑MCP2
improves sound quality and intelligibility by producing consistent audio levels and controlling overloads that produce distortion and clipping at
the DSP inputs.
The RDL HR‑MCP2 is a dual channel microphone compressor that produces consistent audio output levels over wide variations (up to 25 dB) in
microphone input levels. Rear‑panel switches allow setting each output to mic or line level. Each channel can therefore be used as a mic‑level
in‑line compressor or as a microphone preamplifier with compression. The HR‑MCP2 is compatible with dynamic and condenser microphones.
Front‑panel switches are provided to enable low‑cut filters and 15 dB pads for each channel as well as global 48 Vdc phantom power. A CLIP
LED flashes if a signal peak is within 1 dB of clipping. A seven LED metering string displays the instantaneous gain reduction in 3 dB increments.
PRESENTATION AUDIO
Quality Audio System for Boardroom or Conference Room
AN-2070
Description:
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.
BLUETOOTH AND MICROPHONE INPUTS OVER CATx
Format-A with CATx Cable Adds XLR Mic Input at Ideal Locations with Wireless Bluetooth Source
AN-2251
Description:
One Format‑A receiver is used to provide two mono line‑level signals to a local mixer in the equipment rack. Bluetooth L + R summed mono audio is sent to the receiver on pair B. Pair C is used to receive line‑level audio from the Format‑A microphone preamplifier mounted in the room. Audio is connected from the Format‑A senders through CATx cable with standard RJ45 connectors. The use of Format‑A provides flexibility in the location of the senders, simple connection using CATx cable and the economy of a single receiver and power supply.