Adapative delay system (ADS) for sound reinforcement


  • Elliot A. Smith Systems Design Engineering, University of Waterloo, Waterloo, Ont. N2L 3G1
  • Jay S. Detsky Systems Design Engineering, University of Waterloo, Waterloo, Ont. N2L 3G1


Acoustic noise, Adaptive systems, Atmospheric humidity, Microphones, Problem solving, Signal processing, Speech, Thermal effects, Adaptive Delay System (ADS), Electrical systems, Sound reinforcement, Sound systems


At concerts and presentations, the sound system must be carefully calibrated to ensure the entire audience can hear the presenters clearly. For both indoor and outdoor venues, this is done by positioning speakers throughout the audience to reinforce the sound produced on stage. This technique introduces an added complexity, whereby the electrical signal to the speakers in the crowd travels much faster than the sound wave coming from the stage. The Adaptive Delay System (ADS) for Sound Reinforcement is a new method for synchronizing the sound throughout the audience. Unlike existing methods, it does not require complex calculations when initially configuring the sound system. Furthermore, it is also capable of accounting for time-variant conditions such as wind, which are neglected in the current methods of speaker synchronization. Maximum length sequences, a special type of pseudo-random noise, are injected into a speaker for several seconds. A specially placed microphone picks up this sound which is then cross correlated with the original noise to determine the propagation delay. As this sound is barely audible it can be used during a concert to adaptively correct for changing conditions.




How to Cite

Smith EA, Detsky JS. Adapative delay system (ADS) for sound reinforcement. Canadian Acoustics [Internet]. 2004 Dec. 1 [cited 2021 Oct. 20];32(4):32-8. Available from:



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