From the outset of this design, I anticipated using some sort of active crossover and a tri-amplified configuration. This is pretty much a necessity for this sort of speaker, which combines vastly different driver sensitivities. The best active crossover/processor for this design would be the Behringer DCX2496, which is an amazing piece of electronic equipment and will do just about any processing that you can imagine, including 48 dB/octave crossovers, delay, parametric EQ, and other sound-shaping filters. Unfortunately, this unit was unavailable while I was finalizing this design, so instead I used the Behringer CX3400 three-way analog crossover with the Behringer Feedback Destroyer Pro as a parametric EQ.

Thanks to the high-quality drivers with plenty of acoustic overlap, there is a great amount of flexibility in the choice of crossover points. With the benefit of the active approach, it is very easy to dial in the crossover and EQ that works best in your room and for your personal taste. I found that crossover points of about 80 Hz and 1.2 kHz worked very well with this system. While the crossover point to the ribbon can be pushed lower if desired, I found that for maximum output and the greatest clarity, this higher crossover point produced better results. Some amount of equalization on the BG ribbon is a must in this design, and I found I needed to add about a 10 dB notch around 5 kHz, and also needed to boost the output towards 15 kHz. Much of this unevenness in the output of the ribbon is due to the diffraction along the edge of the cabinet. Otherwise, EQ'ing was minimal, and mostly to overcome room effects such as floor reflections and low frequency standing waves.