The SMX-U1 Ultrasonic Microphone is a weatherproof omnidirectional microphone designed for use with the SM2BAT+. This microphone has an Knowles FG element which provides low self-noise, a flat frequency response, and high sensitivity. It can either be connected directly to the SM2BAT+ unit or used in combination with extension cables, allowing you to position the mic up to 100m away from the recorder.
The new SMX-U1 microphones have built-in gain and therefore require lower gain on the SM2BAT and SM2BAT+ than the older SMX-US or SMX-UT microphones. It is recommended that you set 12dB of gain on the SM2BAT or SM2BAT+ for normal recording conditions or 0dB if you are close to the bats to avoid clipping. To do this, you will need to alter rows 6 to 9 of the jumper switches. Set to 6 (on), 7 (off), 8 (off), 9 (on) for 12dB gain or set to 6 (on), 7 (off), 8 (on) 9 (off) for 0dB gain. For more information please see page 7 of the SM2+ User Manual.
Please note that this microphone cannot be used with the EM3+ and is the only microphone available that is compatible with the SM2+.
Recommended Reading
Wildlife Acoustics Microphone Guidelines