IRCS-A Infrared Wireless Classroom System

Advantages of Infrared

Infrared wireless microphone systems are the best solution for classrooms. In today’s RF saturated world a regular (VHF or UHF) microphone system risks interference from a variety of other devices and sources. Cell phones, radios, TV, PA systems, police and emergency service systems, etc., can all interfere with VHF and UHF, but not with IR. Furthermore, infrared is perfect for classroom audio, since, unlike the other systems, IR is short-range, cannot penetrate walls, and is dependent on line-of-sight. This means that a school can have as many classrooms as desired with individual audio systems without fear of interference. Since the Azden system is dual-channel, the teacher can have one microphone and a second person can also have a microphone. In addition, since each classroom system is on the same pair of channels, teachers can go from room to room without having to switch microphones.

Complete Classroom System

Although you can purchase components separately to customize your own system, Azden offers a convenient IRCS-A kit which includes all the components you need to set up a classroom audio system: an IR receiver with ample power for up to 4 ceiling speakers (IRR-40P includes BC-30 power adapter), a chest-worn microphone/transmitter (IRN-10), a pass-around handheld microphone/transmitter (IRH-15c) an external ceiling-mounted sensor (IRD-60), and 4 AA-size rechargeable batteries (1HR-3U) and 2 power chargers (BC-29) for the transmitters.

Components

IRR-40P

2-Channel IR Receiver

The heart of the Azden infrared system is the IRR-40P powered, dual channel receiver. It allows you to use and control the volume of 2 wireless microphones simultaneously, either for “team-teaching” or to use the handheld microphone for students to pass around. The receiver also has 2 stereo auxiliary inputs so that other line-level devices (CD player, MP3 players, VCRs, etc.) can be connected and played through the system. The teacher can also send the audio to a recorder or video camera, using the line-level output jack. For bigger rooms or odd-shaped rooms, up to 3 additional sensors can be attached. With up to 4 ceiling speakers attached to the IRR-40P, sound is spread equally throughout the room, allowing all students to hear equally well.

IRN-10

Chest-Worn IR Microphone/Transmitter

A lightweight, chest worn, microphone/transmitter, the IRN-10 comes with an adjustable lanyard. It is both a microphone and infrared transmitter which wirelessly “links” the teacher to the IR receiver. It has a specially designed internal microphone array which provides great sound pick-up. With two switchable channels, a teacher can go from classroom to classroom with the same microphone! With just two “AA” batteries (alkaline or rechargeable) the microphone can be used the entire school day without recharging or changing batteries. If using the provided NiMH AA rechargeable batteries, they can be charged while installed inside the IRN-10, by connecting the BC-29 wall-charger (note that other battery brands will not be able to charge in-unit).

IRH-15c

Handheld IR Microphone/Transmitter

The perfect handheld “pass-around” microphone for student participation, this dual-channel wireless microphone/transmitter is intended to operate on the IR channel that the teacher is not using (channel setting switch is in battery compartment), but may also be used as the only microphone. It is powered by two “AA” batteries (alkaline or rechargeable) and is compatible with all Azden infrared models. If using the provided NiMH AA rechargeable batteries, they can be charged while installed inside the IRH-15c, by connecting the BC-29 wall-charger (note that other battery brands will not be able to charge in-unit).

IRD-60

External IR Dome Sensor

Designed to be mounted in drop-ceilings, a single well-positioned IRD-60 external IR sensor provides complete classroom coverage in most classroom situations. However, up to 3 sensors can be connected to extend coverage in larger rooms. Mounting is easy, and the sensor is connected to the IR receiver with a standard coaxial wire.

In addition to the components listed above, the IRCS-A kit comes with an AC power supply for the IRR-40P receiver (Part# BC-30), two wall-chargers for the transmitters (Part# BC-29), and four AA size Ni-MH rechargeable batteries (Part# 1HR-3u). Speakers, speaker wire and coaxial cable are not included with this kit.

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Specifications

IRR-40P 2-channel receiver w/ power amplifier

Sub-carrier frequencies: 2.06MHz & 2.56MHz
Type: Superheterodyne – crystal controlled
Modulation: FM
Pilot Tone Signal: 32.768kHz
Frequency Response Deviation: 50-10kHz ±3dB / less than 1%
Audio Output: RCA Jack Mono x2
Speaker Out: 5W x4 @4 Ohms
Line Input: RCA Jack (L & R)
Sensor Input: F-connector x3
Power requirement: 15V DC @ 2.7A (use model BC-30)
Size: 8.03″ W x 9.19″ D x 1.73″ H (204 x 233 x 44mm)
Weight: 3.3lb (1.5kg)

IRH-15c 2-channel handheld transmitter

Sub-carrier frequencies:  2.06MHz & 2.56MHz switchable
Modulation:  FM
Microphone element type:  Uni-directional dynamic
Frequency Response:  50-8kHz ±3dB
Battery Type:  2 – “AA” alkaline (1.5V) or rechargeable NiMH (1.2V)
Battery Life:  > 6 hours / alkaline batteries
Size:  9.65” x ~ 1.375” (245 x ~ 35mm)
Weight:  9.1oz (258g) w/ alkaline batteries)

IRN-10 2-channel chest-worn transmitter

Sub-carrier frequencies:  2.06MHz & 2.56MHz switchable
Modulation:  FM
Microphone element type:  Uni-directional electret x 2
Frequency response:  50-pkHz ±3dB
Ext. Mic input impedance:  2.2 ohms
Ext. Mic input jack:  Ø 3.5mm
Ext. Mic Voltage/Current:  3.5VDC @ 1mA (to power electret mic element)
Mic gain adjustment:  +6dB ~ -10dB
Battery type:  2- “AA” alkaline (1.5V) or rechargeable NiMH (1.2V)
Battery life:  > 8 hours w/ alkaline batteries
Size:  3.15” H x 2.75” W x 1.06” D (80 x 70 x 27mm)
Weight:  4.3oz (120g) w/ alkaline batteries

IRD-60 Dome sensor

Output:  F connector
Power:  powered by receiver (24V @ 15mA)
Cable requirement:  RG59 – 75 ohm coaxial
Size:  3.94” x 1.18” (100 x 300mm)
Weight:  6 oz (170g) w/ mounting bracket

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