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/ Built-in ultrasonic microphone jammer SEL324S Spot

Built-in ultrasonic microphone jammer SEL324S Spot

SEL-324S "Spot" is a high-power microphone (including cell phone microphones) and audio recorder jammer integrated into a common ceiling LED spotlight case, intended for manual installation primarily above desks and tables in meeting rooms.  

SEL-324S "Spot" 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 "Spot" are installed in a thin (the height of the device is 40mm) drum-shaped ceiling spotlight case.

Due to SEL-324S 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 light DC wiring: 12V, 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,
  • Optional wireless RF remote control (Please, send an explicit request for this option during your order).
  • Easy mounting spring brackets.

SEL-324S "Spot" standard package contents:

  • SEL-324S "Spot" jammer, white color finish;
  • Power supply adapter for 12V DC, 2A;
  • Owner's manual;
  • Cardboard shipping box.
Generated noise frequency bandwidth 24 - 26 kHz
Number of ultrasonic transducers 24 pcs
On/off switch presence/absence of 12 V power in line (optional RF remote control)
Average effective jamming range 4 meters *
Power supply +12 V DC
Continuous operation time unlimited
Case material metal and plastic
Overall dimensions D 127 x 40 mm
Weight  not more than 500 g
Operating temperatures from 0 to +50 °C

* Effective jamming range may vary based on type of microphone of the audio device and its relative position to the jammer.