We have received the following message from Wildlife Acoustics which contains essential information for users of the SMX-U1, SMM-U1, and SMX-Horn microphones.
Due to a small number of microphone failures occurring from wind driven rain in our continued testing, we have decided to include protective windscreens with all future microphone shipments. We have also decided to provide windscreens to all existing SMX-U1 and SMM-U1 microphone customers at no charge. Additionally, we will be providing a larger windscreen for the SMX-Horn directional attachment, and again providing these at no charge to existing customers.
Though we did not experience microphone failures in our initial rigorous weather testing of the microphones, some recent failures observed in the field indicate that the microphone element may still be at risk of damage in the event of extreme weather. The main concern is specifically high-velocity wind-blown rain resulting in water spray entering the FG sensor causing damage to the membrane and/or electronics inside. The risk is greater when deployed with the ultrasonic horn attachment. Though we have seen issues with only a handful of microphones, we recommend that you use windscreens for long-term deployments in all areas susceptible to heavy wind driven rain out of an abundance of caution. We view the use of windscreens as a preventative measure to avoid any chance of damage to the microphone element when used in severe weather. For short-term deployments with predictions of less severe weather and in dry climates, you can avoid using windscreens.
The windscreens will attenuate ultrasound by only a few dB when dry. However, they will block most ultrasound when soaked with water, until they dry. Drying time can vary significantly based on temperature, humidity and wind. Given this information, we leave it to you to decide the best course of action for each deployment.
Secure the windscreens for the SMX-U1 and SMM-U1 microphones with the included C-clip. Make sure there is an air gap between the windscreen and the microphone as shown below. (Do not pull the windscreen down tightly).
For the SMX-Horn directional attachment, secure the large windscreen with the included zip-tie as shown below. Exact positioning is not important.
If you have purchased one or more SMM-U1, SMX-U1 microphones or the SMX-Horn attachment from NHBS you do not need to do anything, we will send your microphone covers to you free of charge in the next few days.
Please contact Wildlife Acoustics at support2015@wildlifeacoustics.com if you have any further questions or concerns.