Project background and engineering goals
In 1997, the KF900 Series proved that high-resolution measurements of each individual driver in an array could serve as the basis for an advanced modeling program that accurately predicts total array performance at a variety of locations. Furthermore, by manipulating various DSP parameters, this modeling program could optimize performance and even steer the array’s overall output.
The next year, preliminary work began on a highly compact, single-enclosure array capable of this same control. Over the next few years, experimental prototypes proved the concept to be a valid one, and, in 2001, work began in earnest on what would become the DSA Series.
It may sound redundant to say so, but the primary engineering goal of the project was to ensure that the DSA Series loudspeakers sounded like EAW loudspeakers. Like all EAW loudspeakers, the DSA systems would need to deliver high output, high definition performance within the constraints of its given application. The given application, in this case, was defined as the small to mid-sized installation in spaces with problematic acoustics such as houses of worship, transportation terminals, and museums.
Thus, the DSA Series would need to meet a variety of professional performance standards. Peak output should be in the neighborhood of 120 dB SPL to provide adequate coverage. Since speech intelligibility is a critical issue for these facilities, the system should provide maximum clarity through the vocal range. Broadband frequency response would also be needed to deliver full range music reproduction. Finally, the system would need to deliver outstanding fidelity, an enduring EAW engineering goal.
Often, especially in house of worship applications, aesthetic requirements demand that loudspeakers virtually disappear into the overall architecture. Thus the DSA Series systems should be housed in compact enclosures with a minimal profile. Almost from the beginning, EAW engineers decided to model the DSA enclosures on the traditional column speaker. In addition to minimizing visual impact, this configuration would enable the creation of a line array that was central to steering output in the vertical plane.
To this point, balancing enclosure size against driver placement represented the first substantial obstacle in DSA Series development. While longer lines extend line array benefits to lower frequencies, the applications demanded minimal enclosure size. Therefore, engineers decided to create two different enclosures – a primary full range system (DSA250) and a secondary LF-only system that would extend pattern control when needed (DSA230).
With the basic concepts of the physical design in place, EAW engineers turned their attention to the problems of developing DSP parameters and a control surface that could shape and aim the arrays output in the vertical plane. While the KF900 Series provided some background, the smaller format presented new challenges. Beyond that, any success in steering output above 2 kHz would require even greater precision.
Ultimately, however, it was the goal of creating a total package that delivered easy installation and simple operation that provided the greatest challenge of all. Yet, like all EAW engineering goals, this, too, was met.
Next - DSA250 Design
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Like a KF900 array, each driver in a DSA Series loudspeaker enjoys its own individual amplification and digital signal processing (DSP). Using EAW’s free DSA Pilot software program, users can vary the vertical coverage pattern from 15°to120° as well as aim the coverage ±30°.
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Early prototype of the DSA
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Another prototype shot.
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