In-line systems with electronic reverberators: In-line acoustic enhancement systems include E-coustic LARES (Lexicon Acoustic Reinforcement and Enhancement System), SIAP, the System for Improved Acoustic Performance and ACS, Acoustic Control Systems. These systems use microphones, digital signal processing "with delay, phase, and frequency-response changes," and then send the signal "... to a large number of loudspeakers placed in extremities of the performance venue." The Deutsche Staatsoper in Berlin and the Hummingbird Centre in Toronto use a LARES system.