JSX Acoustic Notes

No single piece of your sound system will outperform well-engineered room acoustics. JSX specializes in small and professional room acoustic design with passive and electronic devices. Jerry Steckling, the Chief Technology Officer of JSX, has pioneered methods for active absorption and the taming of natural eigenmodes.Many researchers have found eigenmode analysis to be a useful tool because of its ability to reveal correlations and patterns in the spatio-temporal distribution of events. Small rooms usually don’t provide the real estate to completely attain full passive control over basic modes, even if even distribution is attained.

The nature of recording rooms, critical listening areas, and home theaters is complex – even when considerable care is taken to treat these sound environments, the eigenmodes can no longer be predicted with standard equations.

These events are oftentimes comprised of a series of underlying events that overlap one another, and cant’ be tracked with a tape measure and calculus functions. Each wall, floor, ceiling surface, and membrane exhibits its own “transfer function,” and each of these objects are not complete reflectors.

If each surface now has its own resonances, the complex nature of each one is an overlay on the total response of the room. If each surface was made of basic sheetrock and stud construction, you would conclude that each would exhibit a certain value of resonance or absorption. However, in most cases, the user has installed diffusing and absorbing devices on those surfaces, which changes the predictable transfer function.

Most complex room cavities need to be measured. Tracking mode effects and their locations can reveal the activity of certain architectural details with respect to the mode patterns. Only then can mode control be applied. The mode patterns of a typical listening facility can be categorized from most to least dominant; these pattern specifications can’t be predicted by the linear eigenmode equations.

When approaching eigenmodes problems (and some are not problems) Typical off the shelf acoustic devices are only effective down to the mid 100s of Hertz. The dominant mode effects below this will often be the wall rigidity, mass, dimension and thus resonances.

An even distribution of mode effects is only part of the desired overall response. The dampening time, the and the centering of the various mode frequencies will also play a large roll in the musicality of the system.

In difference the spatial response in rooms is dominated by room dimensions, speaker placement, the placement of acoustic features and devices and listener placement. Much of this science is not completely subjective. The rules that govern the spatial purity of a room are often psycho-acoustic in nature. The localization of sources are often mapped from previous experiences. Key spatial cues can be masked or revealed by the treatment of especially near surfaces.

Near and far surface treatment techniques should follow basic time domain psycho-acoustic conventions.Jerry Steckling has been working in the area of electro-mechanical control of room mode response as a passion for over 18 years. He has been professionally effective in small room acoustics for high-end listening environments and is an expert in sound field management.



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