SOUND VOLTEX (abbreviated SDVX) is a rhythm game series designed around a similar DJ control paradigm to Konami's beatmania IIDX series, but with a different focus and radically different theming.
In addition to the main four square buttons, the game has two smaller "FX" buttons that, when pressed in time, will apply DJ-style effects to the music being played. As its main gimmick, players have two knobs that essentially control the left and right channels which can be rotated to match on-screen prompts, providing a sort of filter sound effect on top of the music to emulate crossfading.
SOUND VOLTEX does not make use of keysounding, Konami's previously patented system corresponding button presses with song-specific sounds to make it sound like the player is actively playing a song. Therefore, songs can be adapted for the game much more rapidly than in keysounded games. This opens up more kinds of music to be implemented in lieu of a dedicated sound team, with Konami licensing songs from labels like Exit Tunes and Touhou doujin labels as well as holding their own producer contests.