Due to personal time constraints, i'm not entirely sure if i will be able to proceed with this experience. Nevertheless, i want to plan everything, because i would really love to try this If i do, the main purpose will be gathering knowledge and experience. As a secondary purpose, i'm counting the speakers will be able to surpass in dynamics and voicing accuracy mt actual XTZ 99.26 (NeoCD 3/Seas Excell 6.5") speakers. The crossover will be a miniDSP balanced. My knowledge on crossover theory is minimal, but i'm counting that as long as i'm able to take as many measures as its needed, with the help of others with much more knowledge than me, it should be possible to achieve a good result. The selected drivers will be: - Eminence DELTA-12A (8Ω) - BMS 4550 (16Ohm) - Denovo Audio SEOS-12 Waveguide The selected woofer will be the Eminence Delta 12A, available online as cheap as 70-80€. The reason to use this specific driver is cost, as this would be a first experience, and, as such, subject to failure. The BMS4550 will be use as a replacement to the B&C 250, as the price is the same and the BMS seems to be better. There is a Plan B available, as if the active experience doesn't go well, a passive crossover is available here, designed by Bill Waslo: SEOS12 with Eminence 12 Pro Woofers In the long run (2 years?), and if, by then i feel comfortable with the knowledge of designing an active crossover, the plan would be upgrading the woofer to a AE TD 12" with Apollo upgrade (and as TD drivers are used in 10.000$ speakers and are considered the best there is, there will be no need to update for a loooong period ) This speakers will be joining a dual (now single, but dual in the future) BMS 18" subwoofers, that can be crossed as high as 150Hz, and will be symmetric placed near the L/R, so maybe a higher crossover can be used. I've based the design of the speakers on @mattkhan DIY project, as i really like the angled baffle, so the speakers can be pointed directly to the user. The speaker dimensions will be around : 55cm Heigh x 35cm Deep, 40cm Wide. The final measures will be calculated so the waveguide can fire directly to the user ears, so i have to research what is the best way to optimize the waveguide/ear heigh relation. The box has taken into account the diferences in size between the Eminence and the AE drivers. If in the future the drivers are upgraded, and as the AE driver is a few mm wider, the woofer cutoff will need a slight thinning and nothing more. Front Front - x-ray Rear - x-ray PS: a big thanks to @mattkhan for the help with Sketchup project.