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SEL-324A Speaker - Ceiling microphone jammer

SEL-324A Speaker is a high-power microphone (including cell phone microphones) and audio recorder jammer integrated into a common ceiling speaker case, intended for manual installation primarily above desks and tables in meeting rooms.
SEL-324A "Speaker" is a high-power and efficient microphone jamming device due to its thought-out design that includes high-quality directional ultrasonic transducer array that pushes a complex, tailor-made noise waveform on a frequency band that is below human hearing point, but right in the zone of common audio microphone bandwidth, applying a constant noise pressure on the microphone's membrane.
An array of 24 ultrasonic transducers in the SEL-324A "Speaker" are installed in a thin (the height of the device is 40 mm) drum-shaped ceiling speaker case, providing easy deployment into ceiling speaker mounting points, that are commonly available in rooms as mounts for emergency speaker audio systems.
Due to SEL-324A ceiling mounting position, a multipath propagation effect is created, which reflects the generated noise from surfaces and items, further increasing the suppression area and efficiency.
• An array of 24 high-quality piezo-ceramic transducers, controlled by a microchip that automatically shifts the noise signal in time and frequency domains, achieving best possible jamming efficiency and rendering any actual speech signal on the microphone unintelligible.
• Special power supply: device draws power from the standard ceiling speaker DC wiring: 12 V, and starts automatically whenever power is applied.
• Easy to use control: can be turned on/off via presence of power in the power supply line.
• Wireless RF remote control.
• Easy mounting spring brackets.
SEL-324A Speaker standard package contents:
• SEL-324A "Speaker" jammer, white color finish;
• Power supply adapter for 12 V DC, 2A;
• Owner's manual;
• Cardboard shipping box.
Technical characteristics:
Generated noise frequency bandwidth 24-26 kHz
Number of ultrasonic transducers 24 pcs. 
Type of emission interference complex structured ultrasonic noise
Microphone Suppression Directionality perpendicular to the plane of ultrasonic emitters

On/off switch

presence/absence of 12 V power in line / Remote control
Average effective jamming range 4 meters (Effective jamming range may vary based on type of microphone of the audio device and its relative position to the jammer )
Power supply +12 V DC
Continuous operation time unlimited
Case material plastic and metal
Mounting Installation Dimensions (Minimum) D165x40 mm (Minimum)
Diameter 199 mm
Weight not more than 600 g
Operating temperature range 0...+50 °C
Relative humidity no more 85%


Download SEL-324A-Speaker-Manual-ENG pdf

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Download SEL-324A-Speaker-Datasheet-ENG pdf

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