Two or more microphones on the same vertical axis. A stereo microphone.
"I traveled the US and over seas with my show group and made several recordings during the 60s and 70s. I went through some of those 45records and they just were not playable due to being moved around. I really wanted to put them on cds for my kids and sent them to a couple of studios with very little luck i decided to send them to CVC and what ..."