In this lesson you will learn the characteristics of minimum-phase and all-pass systems. A minimum-phase system has a stable and causal inverse. An all-pass system is does not have a stable and causal inverse, but has unit gain at all frequencies. You will see that any system can be factored into the product of a minimum-phase and an all-pass system. A stable and causal inverse exists for the minimum-phase part. This leads to the somewhat surprising conclusion that magnitude response distortion can always be inverted with a stable and causal system.