If you're using PulseAudio on Linux (Linux master race woo!): Lucky you! You can use PulseAudio's monitors! Just open pavucontrol and set the monitor of your main output device to the default input device. If you're using Windows: You need an MP3 player connected to your line in/microphone jack using an 3.5mm cable for this to work. The jack also must be set as the default recording device and you must have listening enabled in the listen tab of the properties window.
See above on how to use. Press Space to Show/Hide the variables. ############################################ #### Special Effects 4: EPILEPSY WARNING!!! ##### ############################################ Turn off the special effects if they lag for you. Put some Dubstep on and you're set. The more Bass, the better.