The Energy 2.8 Veritas ( made in ‘94) were made with a complex crossover intended to minimize impedance changes.
They were made with the option for passive Triamping but the manual explicitly says not to use external crossovers and bypass the internal crossover.
They use special house made aluminum mids/tweeters and I have yet to hear anyone say anything bad about them- engineering/design is more important to the sound than the choice of material .