I have been experimenting with a setup that I have been leaving in the forest unattended overnight. I am currently using SP-BMC-2 mics mounted in a case that I mount on a tripod and recording with a NH900. I set it up at dusk with the mic sensitivity between 13-15, and time marks for 60 minutes. I review the recordings with a audio editor so I can quickly find the parts where there are noises without listening to 9 hours of mostly blank audio. As would be expected, the majority of the sounds are semi-distant. The attached file is an example of this I recorded a month ago. As you can tell, most noises are so quiet that their is a very audible hum when the volume is lound enough to clearly hear the recording. I am trying to improve the quality of the recordings and have decided that I will add a portable preamp. I was hoping that some of you might have some other tips I could try. cackle.mp3