Our newer ultrasonic microphones (SMM-U1 and SMX-U1) have built-in high-pass filters at 8 kHz to cut down on wind noise and other sources of low-frequency rumble. This means that any sound at frequencies lower than 8 kHz will be significantly reduced in volume or completely absent.
Wildlife Acoustics, Inc.
3 Mill and Main Place, Suite 210
Maynard, MA 01754-2657 USA
+1 (978) 369-5225
+1 (888) 733-0200