Xover parts quality,/sound difference?

Huh? Baffled is right....No its not agreed in a friendly sense.. 90% of Standard Speaker DESIGN is crossover is all the point was. And exactly why speakers with NO crossover to worry about are even another step forward. That was not the question and I chose to not confuse the matter or put my own results of eliminating them all together in the original question, eliminate a crossover all together is infact another World as you put it. Do the crossover as well as possible is the best bet, Electronic or no Crossovers is even better, but for the conventional audiophile designs litered with extra parts, Yep go for the better parts and they sound better. Sorry I was not allowed to speak on the matter even though I no longer own crossovers, and this is the exact reason why after experiencing step by step thru many speakers.. But the many I did own and upgraded had very credible increases in sound when using the better parts.. I fail to see where my comments above were to offend or confuse anyone due to my own ownership, but I have to disagree that means I have no way to give info on past endenvors for the best.

By the way the crossover parts I mentioned in most designs will quite litterally require 5 to 10 times the amount of space over the basic 3" X 6" computer grade crossover boards used in many brands. Actually most will require outboard cabinets as big as 12" x 12" for exotic Caps and inductors, not to mention they will weigh in the 15 to 20 lb range vs. the 2 or 3 lbs of the original passive units normally replaced.

D_edwards, keep in mind I was speaking to the majority of audio speaker guys and not trying to push a product I happen to own on to them, simple as that. Thanks for the concern though :)

I have DIY speakers with crossovers I built from scratch. I have use precise calculation to find the right crossover points. On my crossover, I use Dayton caps and dayton ir core inductors. I did find the sound to be much better then the radio shack crossover.

I agree with Sean, it is the construction and layout that shape the sound.

Sure quality parts can be important but the total design is what matters.I do tend to use simple semi 1st order networks with very hi-quality parts in many of my loudspeaker designs also very hi-quality transducers and cabinets.Then like Bobby said its very easy to tell the good from the ugly.In more simple designs with highly complicated crossovers I can skimp on parts costs a bit without much penalty soundwise.

There are also many spots in a crossover that make little difference if you use cheap parts or not. Wasting all your money on exotic caps in a low pass circuit usually makes no sense unless there is a specific design need for it. I will agree that higher end components often sound much better in the mids and highs, but only when properly implemented. A badly designed XO is still bad even with high end parts. In addition, things like silver ribbon inductors etc are extremely expensive, and putting these with a $20 tweeter will not get you a good sounding speaker. There are bargain drivers that sound very good, and some speaker manufacturers are notorious for filling a fancy box with $20 drivers and charging $10,000...however many other incredible sounding speakers use very expensive drivers ranging from ribbon tweeters to ceramic and beryllium mids, so to say these benefit 97% from the crossover is misleading to say the least.

After over twenty years of building and modifying speakers crossover design and components remains a bit of a mystery.
I really think that most good speakers are just a fluke synergy between crossovers components and drivers and something that is hard to replicate in a different set of components.
Of course a lot of experimenting and listening must help but this does not explain why companies with huge research and design resources [Focal,Jamo,Mission,B&W etc]fail to achieve consistently good sounding speakers.Some models are good,others are not,and yet each speaker probably has similar development input.This is also why many cheaper speakers,with cheaper components,often sound better than very expensive ones.
Companies like Spendor and Proac which are highly regarded for the consistency of their speakers and driver integration tend to be very conservative in their model changes and drivers used-as if they evolve new products from long running successful designs rather than designing them from scratch.