inherent design flaws with a 3 way, 15" / 8" / horn (large tower) speaker?

thank you for a great response.  i did order a pair of car audio 15"s as an experiment.  Ultimately I would love to decipher the hundreds of jbl driver model numbers and find something "new but vintage" to drive these speakers. crossover to sub at 80 or 100hz and to the mid at around 550hz. if i can find an 8 that is sufficiently musical from 550-1850 hz (horn-dependent) ill hand it over there (1850 or so). ultimately diy second order crossovers MAX (a great speaker imo should hand over frequencies gracefully back and forth to the correct drivers)
withering feedback welcomed within reason

i am diving in perhaps before im ready.  i did a perfunctory look around at reviews along the lines of, "musical 15 inch woofers" and didnt get enough guidance to make much sense of it.  i ended up purchasing a pair of woofers that are distinctly designed for car audio, due to their construction quality for the price, their handling capacity, and with a recommendation from a youtuber whose projects have inspired me.  Anyway, after the purchase (still havent received) i realize that i was going away from musicality towards thump.  i am correcting my ways.