Sound Card Loopback Modes and Their Respective Applications

[VirtinsTech]

A sound card has four loopback modes: software level loopback, mixer level loopback, hardwired loopback and DUT (Device Under Test) level loopback. The former two are very handy for teaching wave related physics and digital signal processing in class while the latter two can be used to evaluate the performance of a sound card itself and other audio devices.