Sound Diffraction Sphere SBK 130 A The SBK 130 A sound diffraction sphere slips onto the KM 130, KM 131 (D) and KM 183 (D) pressure microphones. While sounds coming from the front-half space are emphasized by up to 2.5 dB between 2 kHz and 10 kHz, sounds arriving from the rear-half space are attenuated by 2.5 dB max in the range above 5 kHz. Inner 22 mm.
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