The Series includes:
Road-worthy construction and efficient truck packing are essential qualities for touring loudspeakers. That means making the systems as compact and sturdy as possible.
The KF850 coaxial three-way design places the HF driver and horn in the LF cone's Wave Guide Cavity to minimize the enclosure volume. Acoustic Refraction Control prevents interaction between the two subsystems.
EAW builds touring loudspeakers exclusively from 15mm cross-grain laminated 18-ply-to-the-inch Baltic birch plywood. This enclosure material is then coated with proprietary urethanes to achieve a hard, durable finish that has survived up to a decade on the road.
Finally, we ergonomically engineered the systems for easy load-in. Easy-to-use flytracks accept industry standard clips. Handles are placed on centers of gravity and only heavy-duty casters are specified.
ARC™: Acoustic Refraction Control™
To create a true three-way system like the KF650 that was manageable in size, efficient use of space was critical. Since the woofer need only handle frequencies up to 250 Hz, we were able to mount the high frequency subsystem within the woofer horn.
Testing in our automated measurement facility revealed that small amounts of energy at the bottom of the HF range were refracting or "wrapping around" the HF waveguide and radiating back down the LF horn. This energy would then reflect off the woofer cone and arrive in the listening area significantly later than the original HF sound, blurring staccato sounds like percussion.
To alleviate this problem, the Acoustic Refraction Control (ARC) device was developed using a proprietary material that would be transparent to low frequencies yet absorb high frequencies. The ARC is mounted in the woofer cavity directly behind the HF horn. It absorbs the reflected HF sound waves while allowing LF energy to pass through unobstructed. While testing this new system, a fringe benefit to using ARC was discovered. Not only does it absorb refracted HF energy, it also acoustically filters harmonic distortion from the woofer which cannot be eliminated by active or passive crossovers. Again, since all ARC filtering occurs above the LF subsystem crossover, the woofer's intended response is unaffected.
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