Here's what Yamaha say about the PSR-SX900:
The top-of-the-line in the PSR-SX Series, the PSR-SX900 delivers the best and most available in its class of Arranger Workstations today.
THE ESSENTIALS HAVE NEVER BEEN BETTER
With a re-imagined user interface, content designed for all styles of music, expandability, customizable functions and controllers, the PSR-SX900 provides all the tools you need to move a dance floor or create your next masterpiece.
BE INSPIRED AS YOU INSPIRE
Perfect for songwriting, the PSR-SX900 is packed with rhythmic patterns (called "Styles") spanning many genres, making it ideal for creating the accompaniment to your musical ideas and an invaluable inspiration for your next composition or arrangement. Together with a tremendous range of expressive sounds and vocal harmony, the PSR-SX900 is your ultimate and inspirational musical partner.
Expansive Soundfield Speakers
The onboard Expansive Soundfield Speakers ensure your performance sounds full and balanced no matter where your audience is. The polypropylene diaphragm provides a crisp, high-quality-ton with excellent response while the new diaphragm structure delivers a balanced sound to a broad listening area.
New Keyboard Action - FSB Keyboard
The new FSB Keyboard offers remarkable playability thanks to its heavier initial key resistance and greater key travel. The refined keyboard structure, with an adjusted fulcrum, allows you to play comfortably even on the backs of the keys whilst upgraded components suppress horizontal key movement.
- 1337 Voices, including 252 Super Articulation Voices, 24 Organ Flutes! Voices. 56 Drum/SFX kits
- 525 Styles, including 463 Pro Styles, 46 Session Styles, 10 DJ Styles and 6 Freeplay Styles
- Pre-installed Expansion content
- Real Distortion and Real Reverb, with an intuitive effects interface
- 1GB on-board memory for expansion data
- 4GB internal memory
- MIDI song file capacity : 3MB per file
- Joystick, FSB keyboard, Sub output, and Expansive Soundfield Speakers for powerful live performance
- Intuitive and fast control with 7" color touch screen and Assignable function
- Chord Looper function
- Mic/Guitar input for use when singing or collaborating with other performers
- Playlist and Registration for quick and easy set up
- Vocal Harmony and Synth Vocoder functions
- Audio Recording (WAV/MP3)
- Voice and Style expandability with the Yamaha Expansion Manager
- 2 USB TO DEVICE terminals
- External display capability
- Bluetooth Audio