This caused issues in locating the Windsor hum, as mentioned in the article. It seems like it should be extremely easy to put up a couple of mics and narrow it

This caused issues in locating the Windsor hum, as mentioned in the article. It seems like it should be extremely easy to put up a couple of mics and narrow it down, but it ended up being a significant technical challenge involving a number of seismic detectors. Low frequency noise is a bitch.