Haters among you may ask, "Since when is a 3-way system a unique technology?"
What's unique is that Mackie is one of the few companies to offer them, and the ONLY company to offer "Active" 3-way systems.
First consider the physics of loudspeakers (we also call them transducers or drivers). A transducer is simply a piston that vibrates room air. The size of a transducer is proportional to the frequency range it's best at creating. If you want to generate low frequencies, you use a big speaker (woofer); if you want high frequencies, you use a small speaker (such as 1-inch exit compression driver). There's also an optimum size for a midrange speaker, too — usually six to eight inches in diameter.
2-way systems use two transducers: high frequency and a low frequency to cover the frequency spectrum — from the highest highs to the lowest lows. This leads to compromise in the midrange. As noted above, size is proportional to output frequency. So in a two-way system, both the HF and LF transducers are being forced to contribute output in a frequency range (mids) that they're not optimally suited to produce.
Worse yet, the cross-over point when one driver leaves off and the other takes over is around 2000Hz. Unfortunately, that's right smack in the middle of the critical midrange frequency band (green area in the drawing). Slight bumps and dips in frequency at the crossover point become very audible.
3-way systems add a third transducer that's just the right size to produce highly accurate midrange. Crossover points fall at the outer edges of the midrange area (green band in the drawing). The LF and HF transducers are freed up to produce only the frequencies that they're best at generating. Audio quality is tremendously improved by adding this third, or midrange speaker, especially since most of the vocals live in the "green" zone. (see Fig. A).
In order to make sure that midrange output "keeps up" with the HF horn, the SA1530z, SA1532z, SA1232z, and SR1530z are the first speakers in their classes to feature a horn-loaded mid-frequency transducer. To smoothly integrate mid and high frequencies, we designed a one-piece, 90° x 40° Optimized Wavefront™ horn that incorporates both the mid- and high-frequency transducers. (see Fig. D)
That's one reason all frequencies above 700Hz are evenly dispersed in the same wide pattern — and everybody in your audience hears the same thing. (see Fig. B) Another reason is the asymmetrical shape of the Optimized Wavefront™ horn system.
In traditional passive 3-way systems, the horn's vertical cross section is symmetrical. Since they both face straight outward, the mid-and high- frequency horns physically point to different locations in the audience. Optimized Wavefront horn design is asymmetrical with 10° of angle upward and 30° of angle downward. This positions the high-frequency section to fire downward into the 6-inch midrange's dispersion pattern, creating a focused, single wavefront, with excellent phase and power response characteristics. That means your audience hears balanced amounts of mid and high frequencies in front of the stage as well as at the very rear of the room. (see Fig. C)