Loudspeaker design: Where to start off?

At the start of the road every loudspeaker designer makes the mostake to jump on at the trendy part of the loudspeaker concepts bandwagon, and want to build:
Complex speakers with 3 ways, in complex cabinets with complex crossovers with modern low impedance drivers. That sort of endeavor requires extreme knowledge and experience to do WELL. Also, because of its complexity, you will not learn what each component contributes to the sound, and you wil never develop useful skills to build upon and evolve efficiently towards the direction YOU want to GROW.
I'm proposing the LEARNING TOOL for kickstarting your journey with BOTH loudpeaker design and improving your hearing skills.

Just remember: if your hearing is not developed, how can your speakers be?
That's why many loudpseakers today are designed for specifications only, and that's why the joy is gone from the sound, and few care about music.