This was recorded with an h6 zoom recorder in zita park. I did this by dropping batteries on a metal covering, figured it could be used as some sort of impact sound.
Just one of a bunch of shoe hits on a metal trash can. I used a home-built contact mic made from a cheapo piezo. This was fed into an h4n and edited in pro tools.
Knocking on a wooden door, like with a metal door knocker, heard from inside a medium size living room. Recorded in stereo with a rode nt5 matched microphone pair.