crossovers are the dirty little secret of most if not all speaker manufacturers. Even expensive speakers often have low quality components in the crossovers. The crossover is invisible inside the speaker, seldom discussed by buyers, and not generally in input into a buying decision. Designers are pressured to save money there as more money is put into a beautiful wood or laquer finish that will close a sale.
I have updated crossovers and spent a lot of money on parts. many of the parts I used were more than 10x the price of the parts they replaced. and the results were dramatic improvement. Not cheap at all, not easy as it was a lot of work, but like most efforts to squeeze out the last 2%, rewarding if you don't worry about the money.
The idea is rejected by many, trying to justify it by saying the designer "voiced" it with the ocmponents provided. I think they are hoping a new "pandora's box" of upgrades doen't catch on that they will be forced by thier own need to keep up to spend money on. They don't really want to know that this upgrade is out there. Do you realize that for most consumer goods the designer is given a parts budget that is about 10% of the sale price? that includes cabinet, drivers, crossover, and anything else they need. so corners have to be cut. If you, the consumer, don't need to cut corners, this is a worthwhile upgrade.
Jerry