I am also a big fan of DIY speaker projects.
Zalytron is a great source for parts, there are several other North American retailers of parts from companies like Accuton, Axon, Dynaudio, Eton, Focal, Kimber, OrcaDesign, Raven, Seas, Solen, Vifa, the list goes on and on.
My only caveat about Zalytron kits is that the crossover designs are for the most part from the late 80's - 90's. A lot has happened since. Mostly, the simplification of networks mandated by the return to lower powered amplification(tube/OTL/SET). Whereas these kits often feature third order crossover topologies, in my opinion, gains can be made by investigating things like first and second order networks. Also, running drivers with no parts in the circuit and series networks can produce stunning results. Just one person's opinions.
To maximize impact and what a driver will produce, please use the best crossover components your project affords. For example, using a 12 gauge coil in place of an 18 gauge will pay dividends far beyond the cost. Film and foil caps are not always necessary(especially on a novice - mid level project), but certainly a good polypropylene along the lines of SCR, Axon, WonderCap is worth it. And, the best value in DIY speakers are wirewound resistors. For a maximum of $15/project, the clarity and reduction in harshness, grain, sibilance, and shrillness cannot be bested. Also, do not skimp on the quantity and quality of the internal wiring.
Good luck!
Zalytron is a great source for parts, there are several other North American retailers of parts from companies like Accuton, Axon, Dynaudio, Eton, Focal, Kimber, OrcaDesign, Raven, Seas, Solen, Vifa, the list goes on and on.
My only caveat about Zalytron kits is that the crossover designs are for the most part from the late 80's - 90's. A lot has happened since. Mostly, the simplification of networks mandated by the return to lower powered amplification(tube/OTL/SET). Whereas these kits often feature third order crossover topologies, in my opinion, gains can be made by investigating things like first and second order networks. Also, running drivers with no parts in the circuit and series networks can produce stunning results. Just one person's opinions.
To maximize impact and what a driver will produce, please use the best crossover components your project affords. For example, using a 12 gauge coil in place of an 18 gauge will pay dividends far beyond the cost. Film and foil caps are not always necessary(especially on a novice - mid level project), but certainly a good polypropylene along the lines of SCR, Axon, WonderCap is worth it. And, the best value in DIY speakers are wirewound resistors. For a maximum of $15/project, the clarity and reduction in harshness, grain, sibilance, and shrillness cannot be bested. Also, do not skimp on the quantity and quality of the internal wiring.
Good luck!