For an audio device such as a tape recorder, the MOL is generally taken to mean the output signal level that results in 3% harmonic distortion at low frequencies and usually 3% intermodulation distortion at high frequencies. Any higher signal output than the MOL will result in rapidly increasing distortion, and is a function of both input signal frequency and of the device itself. MOL also applies to a specification for analog magnetic tape. The MOL for a tape is frequency-dependent; all magnetic tape saturates faster at higher frequencies; it is also speed-sensitive: as the recording speed is slowed, the distortion point is lowered. MOL may be referenced to an absolute flux level, or to a test tape.
See third harmonic distortion.