Here are some recordings of drones from the vents in the side of one of the buildings in the central area of the University of Edinburgh. All were made using a Sound Devices 702 and a Rode NT4 in a Rycote windshield. These were the first recordings I’ve made using the 702. I had the low cut filter engaged but there’s still a bit of sub bass rumble going on so I might try raising the cutoff frequency next time. The files are normalised but otherwise unedited.