Resources

"Adapting Loudspeaker Array Radiation to the Venue using Numerical Optimization of FIR Filters", paper presented at the 135th AES convention, New York, NY, USA 17-20th of October 2013. Paper Number 8937.

Link to the paper in the AES Online E-Library. (You have to be a member of the AES online library. Please note that subscription costs are low.)

Stefan Feistel
AFMG Technologies, Berlin, Germany

Mario Sempf, Kilian Köhler, Holger Schmalle
IBS Audio, Berlin, Germany (See the document for exact affiliation information.)
 

Abstract
Over the last two decades loudspeaker arrays have been employed increasingly for sound reinforcement. Their high output power and focusing ability facilitate extensive control capabilities as well as extraordinary performance. Based on acoustic simulation, numerical optimization of the array configuration, particularly of FIR filters, adds a new level of flexibility. Radiation characteristics can be established that are not available for conventionally tuned sound systems. It is shown that substantial improvements in sound field uniformity and output SPL can be achieved. Different real-world case studies are presented based on systematic measurements and simulations. Important practical implementation aspects are discussed such as the spatial resolution of driven sources, the number of FIR coefficients, and the quality of loudspeaker data.

Practical benefits:
The paper can serve as an introductory guide to the topic of FIR filter sound system optimization and especially AFMG’s FIRmaker. It can be useful for those who are interested in advanced sound system design. Since the technology is already available and the advantage over conventional design has been proven theoretically, experimentally and practically, professionals may start using FIR filter optimization more often or even in every single relevant project.