Here is my recording of the 4th of July for 2016. The microphones cost less than two dollars each, and the phantom power adapters were under fifty dollars apiece. Well worth it, considering there are other solutions costing hundreds. I grounded the metal frame of the window where one of the microphones was placed, due to hum pick up. There are power lines parallel to the window about thirty feet away. I measured several volts of alternating current between the metal window frame and the Mackie mixer. The ground wire worked perfectly, eliminating all hum from the audio.
Direct mp3 download or play: 4th of July Ambience 2016 – Part 1
Direct mp3 download or play: 4th of July Ambience 2016 – Part 2
Direct mp3 download or play: 4th of July Ambience 2016 – Part 3
Direct mp4 file download or play: video commentary
phantom power adapters (more information here)