This 2-channel DJ controller from Pioneer connects to rekordbox, Serato DJ Lite, djay, and Traktor Play, giving access to multiple DJ applications from a single piece of hardware. The DDJ-FLX4 ships in white and works with PC, Mac, iPhone, iPad, and Android devices via USB or Bluetooth connectivity. Smart Fader technology automatically adjusts volume, bass, and BPM during transitions, while Smart CFX applies multi-effect combinations with a single knob turn. The layout mirrors professional Pioneer DJ products but keeps the footprint compact enough for mobile use. The controller includes a built-in sound card that outputs audio via RCA connections, eliminating the need for external audio interfaces. Eight backlit rubber performance pads trigger Hot Cues, Pad FX, Beat Jump, and sampler functions across both decks. A microphone input with dedicated volume control allows MC work or live streaming without requiring separate mixer hardware. USB Type-C connectivity supplies both power and audio when connected to compatible smartphones, while PC and Mac users can power the unit directly through the USB connection. The tempo slider range switches between +/-6%, +/-10%, +/-16%, and WIDE settings via the BEAT SYNC button. Beat FX controls adjust effect depth, channel assignment, and beat-sync length independently. Rekordbox integration enables streaming from Apple Music, Beatport Streaming, SoundCloud Go+, Tidal, and Spotify services directly through the controller, with subscriptions required for each platform. The DDJ-FLX4 includes plug-and-play operation on both Windows and Mac systems without manual driver installation. Firmware updates deliver automatically through the included Firmware Update Manager software. The controller's high-pass and low-pass filter controls operate in tandem with effect assignments from the connected DJ software, while the BEAT SYNC function automatically matches tempo and beatgrid alignment with the master deck. Features 2-channel DJ controller compatible with rekordbox, Serato DJ Lite, djay, and Traktor Play Smart Fader automatically adjusts volume, bass, and BPM during track transitions Smart CFX applies multi-effect combinations with single knob control USB and Bluetooth connectivity for PC, Mac, iOS, and Android devices Built-in sound card with RCA master outputs for direct speaker connection Eight backlit rubber performance pads for Hot Cues, Pad FX, and sampler Microphone input with dedicated volume control for live streaming and MC work Tempo slider range switches between +/-6%, +/-10%, +/-16%, and WIDE settings