3D Surround Controller is a MIDI-over-Wifi based surround sound controller compatible with hardware that can receive MIDI control change messages, such as xSpat BoX2 from A&G Soluzioni Digitali, and (x & y only) the Yamaha 01v 96. To use the controller, you must have the DSMidiWifi server (a free download) installed on the host computer. 8 sound sources can be moved in a true (x, y, z) 3D space by using a combination of the iPhone's touch screen, and the accelerometers. Smooth transitions can be triggered as well. The MIDI parameters (control change value, and MIDI channel) can be edited in 'Settings', so this app should be useful to anyone who has suitable hardware that responds to MIDI control change messages.