Yamaha SK-AFC3

Yamaha SK-AFC3

For over 125 years YAMAHA craftsmen have created some of the world’s finest musical instruments. Superior sound quality has always been the driving force behind all of Yamaha's efforts. Whether manufacturing instruments, developing state-of-the-art audio technologies or designing performance halls and theatres, Yamaha is always seeking new ways to deliver the best possible listening experience.

First implemented by Yamaha in 1985, Active Field Control (AFC) is an acoustic conditioning system designed to adjust and enhance the architectural acoustic characteristics of facilities such as performance arts venues, houses of worship, theatres and concert halls—while maintaining the natural sonic characteristics of the space.

AFC3 represents the third generation of innovative Active Field Control (AFC) systems from Yamaha, the most trusted name in audio.

With increasing pressure for facilities to become more multi-purpose and accommodate a wider range of applications AFC3 provides a cost-effective alternative to mechanical means of modifying room acoustics. A truly scalable solution which can be installed in a wide range of venues AFC3 makes it possible to hold classical concerts in a very large hall without a sound reinforcement system, to accommodate an organ in a small church, or to enhance crowd response in a stadium. Reverberation changes can be made at the push of a button, allowing the performance environment to be adjusted almost instantly. In addition AFC3 is able to deliver the same high-quality sonic experience to every performer and member of the audience.

Yamaha AFC systems are currently installed in over 80 facilities in the U.S. and Japan, and now with the release of AFC3, a much wider range of facilities worldwide will now have access to the best acoustic enhancement system available today.

AFC Concept
Increasing the sound energy density can extend the reverberation time in a room.AFC utilizes the acoustical feedback of a system to increase the energy density of diffused sound. Reverberation time and sound energy density can be controlled with transparency while preserving the original acoustical characteristics of a room.This technique distinguishes AFC from other enhancement systems.

EMR (Electronic Microphone Rotator)
Since AFC utilizes acoustical feedback, it is essential to prevent coloration problems caused by a closed loop condition and maintain a stable system. In order to ensure controlled loop gain and a sufficient margin against instability, AFC implements a special patented technique called Electronic Microphone Rotator (EMR).

Wide Range Controllability using FIR Filters
AFC uses an FIR filter in the feedback loop which provides one of the controls of the AFC enhancement process. For example, by adjusting the gain of the FIR taps, the system will adjust the energy added back to the room in the feedback loop, changing the effective absorption of the room / system and resulting RT.

Effectiveness Independent of Source and Receiver Position in the Room
AFC brings effective results to the entire targeted room by using a feedback loop-based control.