Back in the 1960s AR marketed their AR3a loudspeakers with a live vs. recording demonstration. A string ensemble, solo violinist or guitarist would play a piece and at some point the sound would be switched to a recording. Listeners would then be asked to comment whether they could tell when the switch took place. The majority of listeners could not accurately detect the switch over. A key element of the demonstration was the special way the recordings were made. They were made either outdoors or in anechoic chamber to avoid the "double acoustic space signature" effect during playback.
