Quads are effectively a point source panel. Very different than others. They run twice the voltages, use reinforced perforated plates as stators as opposed to wire. They have less than 1/2 the the clearances and diaphragm thickness (mass) of everyone else. It's why they are easier to arc but at reasonable volumes, untouchable. If you can find a good pair of the originals that came out on 1957 (different all stat 3 way), know how to setup and nearfield them (about 6') they are still as good as anything. You can't curve a large unsupported panel because the diaphragms bow. You don't want a large panel with highs coming from everywhere because you get time smear. That soft undynamic airiness many panels have. On the original quad, the tweeter is 1" wide and the new one highs are limited to about an 8" circle.
When you look at a Logan, you will see it actually behaves as over a dozen small stacked horizontal panels. The diaphragm is continuous but has over 15 horizontal curved supports. That really limits excursion as does the fact the even at that small individually supported height, the panel itself bows so needs more clearance (less control force). They are more durable because they don't generate enough force, control or excursion to perf the heavier diaphragm. There's a reason they have no bass without woofers and if you look at their high end, add on electrostatic woofers, you find that they are large flat panels. The curved panel is a poor solution looking for a problem. If you're looking for that typed of sound field, you'd be much better off with a Soundlab.
Honestly, if you like electrostatic type detail with more power handling, you're better off with a dynamic speaker with and a well integrated ribbon tweeter like a better ProAc. True transformer coupled, small folded aluminium Ribbons can still beat an electrostatic at the top end. Do not confuse with a planer magnetic driver which are generally meh.
If you get a chance read about the newer quad delay lines. The drivers are supported as 4 large panels with concentric rings in the stators to form a delay line that mimics a point source a foot behind the speaker and why 10 feet or more away is optimum. Takes about that to get a seamless effect.
of the game.
