There's lots of discussion about FRFR and the various choices available. But I was always under the impression that building a FRFR speaker (the holy grail of high-end stereo systems) involved more than just building a box and throwing a driver into it. I never hear any discussion about what the newer FRFR offerings have done to achieve FRFR status. Seems like all the drivers are off the shelf and similar to the drivers that you find in standard cabs, the boxes look similar in size and shape to standard cabs and wedges, so where is the engineering "magic" that somehow integrates box, driver, and cross-over into a system that gives you a flat frequency response over a wide range. I suppose that one answer might be that typical guitar cabs are the ones that intentionally deviate from FRFR to achieve their particular qualities and that if you don't do those things, FRFR is what you get by default. But somehow, I doubt it. Anyone have any thoughts about what it takes to make a FRFR speaker and what the newer FRFR offerings out there have actually done to achieve it?