The Official Amina Blog

The dispersion characteristics of the Amina in-wall speakers are half sphere, 180 degrees. Even at 85 degrees off-axis, the listener still gets the same type of frequency response as those that are sitting on-axis to the speaker (the panel produces a figure-8 di-polar response front to back in free air, resulting in a 1/2 sphere once isolated by a wall). In stereo reproduction the “sweet spot” is no longer a single location, rather the stereo spectrum can be enjoyed throughout the room. Over the complete half sphere dispersion angle there is no discernable change in frequency-power response. All frequencies, including the high-end, remain virtually the same.

This has been verified in measurements done by the University of Delft, a copy of which is available in PDF format. This dispersion cannot be achieved by point-source cone shaped or dome shaped piston-driven devices, nor by ribbon arrays. It can only be obtained by utilizing a technique that creates thousands of point sources, in other words, a defused soundfield. The TUD measurements, as well as polar plots will allow a trained Audio designer to quickly ascertain that the products’ performance are like no other equivalent product, and studying these measurements will aid in the understanding of the concepts of AIW technology. The 180 degree dispersion pattern, combined with a longer path of consistent amplitude allows for less units within the same space, as the rate of loss-over-distance is substantially less than conventional speakers with each doubling of distance, much like the behaviour found in line array technology (inverse square law, equal to 6db loss for each distance squared from a single point source does not equate with planar ribbon-like devices due to the constructive addition of multiple point-sources within ½ their wavelength). Just to compare, whereas sufficient coverage over a certain area would require the use of four conventional speakers, a single AIW would provide an even superior coverage. Less product to install, less interfering point sources, hence higher intelligibility.

Filed under: Application Tips, Features / Specs on January 17th, 2008