This also a reply to you on the other thread. A crossover is not necessarily a problem if it's done properly and the two drivers being crossed over have very similar characteristics (something that is not looked into very often and which may be blamed on the crossover)

Every driver has a sonic signature - A ribbon produces a given frequency differently than a metal dome or paper or silk or diamond etc. And that also applies to the woofers. There is a "handoff" or point where the woofer and tweeter are reproducing the same frequencies. You could have terrific crossovers and measurements but it doesn't mean you won't hear that step as annoying. The appeal of two way speakers is that there is only one crossover - in a 3 way you have two crossovers and it's very difficult to get it all to mesh.

So you might say - buy a single driver and avoid the whole porblem by not having a crossover. That's fine it solves one problem but adds other problems. The one driver now has to be able to create the nuance and subtle shadings of microdynamics and also has to produce bass at level with impact and finer subtleties of the treble band from a single driver. Generally the good ones like Teresonic have a rather large cabinet that can extend the bass frequencies in some sort of Transmission Line or Quasi Transmission Line. The Teresonic Ingenium does a terrific job and extends into the lower regions very well. Treble is extended and the midrange is fantastic. The compromise is the bass dynamics of rock is thinned out because at high volumes the speaker is still trying to do it all. So there is a slight slowness to the bottom end that basically compresses. This is a minor quibble if you listen at moderate volumes and music suited for it. Heavy rock you would want something else.

Crossovers and boxes are not the problems - the fact is most (the VAST MAJORITY) speakers are multi-way and use crossovers. And the thing is most people hear bad examples of these and conclude that all boxed speakers and all speakers using crossovers are bad. It's not unlike people who rail against American movies. All American movies open in theaters in North America - and msot of them are terrible. And it seems like the import films from Russia, France, Germany etc are so much better - yes but the films that get imported here are the "best" of the films from those countries - we don't get the piles and piles of abysmal films they put out - we get their Cannes award winners and academy award nominees in the foreign film department.

There may 5% of boxed speakers with crossovers that sound very good. It's very possible that people have not heard a single boxed speaker that falls in the 5% "great" camp.