they do not sound like electrostatic speakers, magnepans, apogees, eminent technology speakers and other planar magnetics.
MrT,
Forgive me for being presumptuous but I do believe that you are confusing things. At least this is the only way I can reconcile your statements/preferences.
The biggest difference in all these electrostatic designs compared to almost all the cone speaker designs is NOT in the timbre but in the radiation pattern!
I think it is the RADIATION pattern of panels that is what "turns your crank".
It is entirely possible you prefer the enhanced reverberant sound field that you get from a large panel! This is perfectly understandable. However, claiming that the timbre of "all cones is wrong" is simply not supported by any science that I know of. I call this panel sound an atmospheric effect...dipoles do it also but not as significantly....it is almost magical and the sound from panels can at times be enveloping and almost three dimensional - sometimes with a distinct source between the speakers but more often not. It is also possible to hear increased emphasis in certain stringed instruments and vocals due to the later reverberant information that reaches the ears (reverberation spreads out the energy and gives the ear/brain more chance to discern things/details). In fact the sound can be highly variable depending on both placement and listening position (you also tend to get a lot of comb filtering/lobing with such large radiating surfaces and reflections, which changes the sound of long lasting notes - although the spacing between the ears generally compensates for the comb filtering and you are left with just an impression of "spaciousness" in the sound rather than a change in tone/timbre). The highly variable nature of the sound ( due to room interaction ) is why these panel designs are shunned in studios....studios want translatable and reproducible sound....they want to know exactly what a mix or master sounds like ....NOT what it sounds like in a particular room! Besides the dynamic comression from panels is just a non starter for evaluating a mix.
Of course, the acoustics that a large panel may create in your room are probably more akin to what you might hear towards the back of a large concert hall where there is a heavier emaphasis on reflected rather than direct sound ( defintely true of classical and church music compared to typical rock/pop/jazz club/concert sound). Indeed, if you only attend the ballet and opera then you will ONLY hear reflected sound from the orchestra that sits in a pit. The comb filtering (from multiple reflections of the same signal all reaching your ear but with various delays) has a marked impact on what you hear. Even a symphony orchestra which sits on a wooden floor is gaining from a huge amount of reverberant energy off the floor. Contrast this with an amplified rock group with speaker towers and of course the sound field radiation pattern is completely different!!
I propose that your beef with ALL cone speakers and you adoration of all panels (especially Quad 57) has absolutely nothing to do with timbre. IMHO, you are mixing your terms, which is understandable given the complexity of a natural sound field, the nature of audio reproduction in a room at home and the difficulty in translating your perceptions into language...