In the 1960s Decca recording engineers experimented with ways of improving stereo recordings. They created a technique they named "Decca Panoramic Sound." The term "Deramic" was created as abbreviation of this. The new concept "allowed for more space between instruments, rendering these sounds softer to the ear." Early stereo recordings of popular music usually were mixed with sounds to the hard left, centre, or hard right only. This was because of the technical limitations of the professional 4-track reel-to-reel recorders which were considered state of the art until 1967.