You old timers are about to open a doorway into an abyss of information and misinformation regarding loudspeakers and loudspeaker enclosures. Everything that can be said, and needs to be said, has already been said at least fifty years (or more) ago. OTOH, putting together my very own DIY speaker has never crossed my possibilities threshold. Unless the basket, voice coil, spider, cone, electrical terminals, braided flexible wire, rubber mounting thingy, and glue are all readily available at nearly no cost... why bother? And if such things are available nearly free, why not spend a few cents more and let third-world labor assemble it for you? Assuming they know what they are doing of course.
Audiophiles have been arguing since the 1950s as to which speaker manufacturer makes the "best" loudspeakers and what kind of enclosure to put it in. Are we ready to go down that road yet again, this time with the added uncertainties of a do-it-yourself speaker construction? Well, yes, probably. This is of course a hobby forum site, after all is said and done. Just be prepared for some epic length threads and a lot of acrimony among the participants. I think I will sit this one out.
@Prohor the first three questions you asked are good ones, but they also reveal that you are in no way prepared to design and build your own loudspeakers. Magnets: bigger is better. Voice coil: short, stiff, low mass, high current capacity. Cone: stiff, low mass, non-resonant, with ultra-compliant outer edge and spider. Good luck finding all that. This is for bass to mid-range (100 to 500 Hz tops). To produce the full range of audio frequencies requires multiple speakers, and often different technology than a "simple" voice coil driving a cone. But you did say you wanted a bass speaker, so press to MECO.
If you really want to learn how to design your own loudspeaker, and proceed to actually building it, you need to learn how they work: the physics of loudspeakers and how they interact with the environment surrounding them. A good place to start is
this article in PDF form that you can download from the Internet and read. It uses some college-level math, but overall is a good preview of the things you need to consider. It provides zero design information, but it sets you a path for further understanding.
So, let's get this thread rolling...
