Head Gap

In tape recorders and tape heads the gap, or head gap, is the space created where the poles of the magnet making up the guts of a tape head nearly meet. These poles are magnetically charged with electric current (just like an electromagnet), and this gap area is where the tape passing over is acted upon by the magnetic fluctuations of the electromagnet. The size of the head gap is critical for optimal audio recording results. It determines how large an area of the tape can be magnetized, and it also determines the smallest area of magnetization that can resolved when the tape is played back.