I think going back to the title of the thread, you've got to face some uncomfortable truths here. I'm not real hifi cognoscenti btw - just on the back of 40 years of buying it, and a few DIY speaker builds along the way.
Just look at the pictures in this thread. There's a thousand ways and more to get sound waves out of a box. Your first mission is to choose even a rough general idea - 2 way, 3 way, 7, horn, array, passive, DSP.... yada yada yada... Many of those you won't even have heard in something close to your listening setup. If you buy expensive, retail speakers you'll almost certainly get the chance to audition them with your kit, and probably in your listening room too. So you're not *completely* in the dark. If you DIY - yes, you'll save a bit of money (or more accurately buy some time from yourself
), but you have to accept that you're taking an expensive, hopefully educated, but a gamble nonetheless. Because the chance that you can hear the set you're interested in is minimal, even assuming you're going with a published design. The chance of hearing them with your kit in your room is, let's say zero to keep it simple. So on the basis of other peoples' opinions on maybe similar designs, but in different circumstances with different kit, you still have to be prepared to lay down 4 figure sums in kit and raw materials without any real clear idea what'll happen at the end. And if you can embrace that, it's loads of fun
I really like making speakers, but I'm not going to fool anyone - especially myself - that I've got anything but the roughest idea how they'll sound once I've finished. If your objective is from the start - "These are the last speakers I will ever own", then you may need to think about that a bit before you start.