To meet the requirements for our bandwidth, dynamic capabilities and low distortion, all manner of technical solutions are brought to bear upon the challenge. These lead to beautiful measurement curves on paper and great-looking designs big and small. However, one common thing that all loudspeakers sooner or later confront is the listening room of the eventual owner. The moment a speaker is placed in a room and connected to the electronics that drive it, the room literally takes over. Sund waves travel at roughly 345 meters per second. With sound coming directly from the loudspeaker thus not reflected from a boundary, it will reach the listener between 0.01 and 0.2 seconds late depending on distance. If this were consistent, there'd be no problem. However, a source not only produces direct sound but reflections. These are semi-distinct delayed returns from various reflective surfaces. In a room there are walls, ceiling and floor. Reflections from these reach the listener about 50 to 80 milliseconds after the first direct sound. As these reflections have traveled a longer path, they have lost amplitude or power along the way. Reflections that arrive after the early reflections are called late reflections. As these have traveled an even longer path, they have lost yet more amplitude or power along the way. These reflections merge and form the reverberant signature of the room. The bigger the room, the longer the path for late reflections and the stronger the reverberant sound field. Normally direct sound decreases by 6dB for each doubling of distance.

We are able to perceive the source of a sound based on its direct sound arriving at our ears. Early reflections that arrive 50 to 80 milliseconds after the direct sound are not perceived as separate. Their latency is too short and our ear/brain sums these data into the direct sound. From these facts we can construct a room optimal for music reproduction. There should be an optimum reverberation time that provides clarity, sound intensity and liveliness. Clarity requires short reverberation time, sound intensity requires a high level of reverberation while liveliness is related to longer reverberations. In a room designed for sound like a theater, concert hall or congress facility, the reverberation components can be optimized. But can we do that in our average listening room? Only a very few lucky audiophiles command a dedicated listening room that could be acoustically optimized. Simple mortals like us must live with sub-optimal rooms. But that shouldn't be too big of an issue if the speakers were designed accordingly.

Saša Burian is fully aware of the challenges involved. From experience he knows that to meet the requirements, the resulting loudspeaker will be large, cumbersome as he says and above all very heavy. Only compromises will overcome these facts but also diminish sound quality. For his Audio Alto LA17, Saša chose the open-baffle concept to begin with. None of the drivers are confined to a conventional cabinet. Sound radiates both from the front of the driver and its back. Using dipole dispersion avoids cabinet-related distortion. If it's not there to begin with, it can't cause trouble.