C - crossovers.
Cabinetry, ala veneers and finish rule the day, with exotic drivers following closely behind. Cetainly a smart strategy, as this hobby is one where people listen with their eyes and their wallets.
However, in my own experimentation, by varying the cap/coil ratio, I could make my own loudspeakers become as forward and white sounding as a pair of Lumenwhites or as lush and full-bodied as Vandersteens, and of course, anything in between those two points.
Along those lines, the unfortunate thing is in this day and age, we are as far away from having competent people designing crossovers as we have ever been. Why? So many of the people designing loudspeakers today are deficient in mathematics; to the point where they run away from it.
For example, one loudspeaker manufacturer who I know, and has won awards at shows got his crossover design from a "friend" in the business. When I looked at it, the numbers were so far off, I jumped up to ask him how he came up with such off the wall(being kind) values, which is when he told me. Knowing the friend's talents lie in many areas of loudspeaker optimization, but not in designing (although he surely can upgrade/mod them to improve sonics) crossovers or mathematics, I approached the friend about the design, and he admitted he knows almost nothing about how to design a crossover. Where did he get these values? He kind of mimicked another speaker on the market he liked, but wasn't 100% sure if he was using exactly the same values. My money says that given the difference between commas and periods on either side of the Atlantic, a decimal point got lost in translation. What's worse is that even after a fundamental and major redesign of the speaker, the crossover has not changed one iota, "I have a crossover that works, and am afraid to mess with it." Really? I've told him the more appropriate values several times, but hey, the parts have already been bought and paid for.
