The question is of course in reference to loudspeakers with multiple dynamic drivers and crossovers.
Electrostatic, magnetic-planar, and ribbon designs can be a different kettle of fish. For instance:
- The QUAD 63 gained notoriety for---amongst other attributes---the ability to recreate a square wave, which requires extremely good---close to perfect---time coherency.
- The Eminent Technology LFT-8b features inventor/designer/builder Bruce Thigpen’s Linear Field Transducer, a push-pull magnetic-planar driver which he employs to reproduce all frequencies from 180Hz to 10kHz, with NO crossover! The midrange (LFT) to tweeter (a ribbon) crossover at 10kHZ is symmetrical 1st-order, as is the 180Hz LFT to dynamic woofer.
On the other hand, Magnepan’s crossovers flip the polarity (180 degree opposite each other) of the various drivers in most of its’ models. Few Magnepan owners have heard---or are even aware---of the ET LFT-8b, but it is considerably superior---imo---to the MG1.7i, and about the same price ($2499/pr).