You'll notice the Econowave uses the same basic crossover circuit, with a bypassed tweeter attenuator providing slightly underdamped tweeter filter via the R1/R2/C1 network used in π Speakers. That makes perfect sense because it compensates for tweeter power response and matches directivity between midwoofer and tweeter. Those are the requirements for a design like this.

There are plenty of good woofers suitable for this kind of speaker. I tend to like a slightly overdamped vented alignment, which I feel gives the best overall performance in terms of size/extension/efficiency and it also works out well to conjugate room gain in typical home hifi listening rooms. It's also a great match for distributed subs, providing adequate overlap for blending and smoothing rooms modes.

My favorite woofer for this application is the JBL 2226, which is what is used in the four π loudspeaker. The JBL 2226 incorportates a shorting ring for low distortion. The cone is well-damped for smooth midrange, a requirement for the crossover frequency needed for a matched-directity two-way speaker. It provides good extension in a relatively small package, so subwoofers aren't a requirement. It also blends well with distributed subs, making it a very versatile speaker.

• four π performance data