1 comment The 4x is the last digital signal processor designed by the Italian physicist Giuseppe Di Giugno and developed at Ircam. The 4X processor is a single element of a more complex system for computer music named simply 4X System. 4XJuly 8, 2013 in TOPICS tagged 4X / Giuseppe Di Giugno / Max/Msp / Synthetic Performer by Alex Di Nunzio (updated on July 15, 2013)