The "bass panels" also almost play fullrange to be honest. i measured them once and there is only a small rolloff but its above 10khz. but yeah top and bot usually are called hte bass panels: )
Same for the Magnepan Tympani bass drivers but that is measured not what they sound like. Of course, really different moving mass of their diaphragm compared to an electrostatic.
With my 2805 (same panels, different frame) it was not possible to remove the lower bass panel without first moving the next panel up. 63s may be easier, I wouldn't know.
You are correct, that is the way to get the bottom panel out in my experience with all versions of the modern quads.
Sheldon
Same for the Magnepan Tympani bass drivers but that is measured not what they sound like. Of course, really different moving mass of their diaphragm compared to an electrostatic.
the magnepan tymps are crosses Much much lower. the tweeter is crossed at 1200 or something. the 'bass' panel does have a slight rising responsebut what they produce above 10Khz is not all that much. since there is a problem at 15Khz so they want it to be down before that without much influance on the tweeter.
Pretty sure the bass panels (and outer edges of the mid panels) are crossed over using a first order crossover consisting of series resistance and the panel capacitance. I think it starts to roll off at about 500Hz or so.
Sheldon
Sheldon