I guess I should apologize for the lack of interest in this thread, Bob. It is surely a sad day that we have come to when some of the finest loudspeakers ever manufactured generate absolutely zero interest.
While I have absolutely no experience in modding them, I hope you don't mind me brainstorming a little. Personally, you could always try the usual suspects, just go for better quality. Yada, yada, yada. It is very likely that this will take the speakers a step up, as there was nothing equivalent to the big North Creek coils back then or the good caps of today. One caution I would say if you have to replace a big cap is to do it with smaller caps in parallel to lower the ESR.
Again, I am a bit worried about giving specific advice, as there is the very real possibility of taking the sound a step back, but I do remember sites where they discussed crossover upgrades.
One thing I might try if I had the time and energy is some experimentation. Basically, a lot of the Apogees were more or less dead shorts, especially the early ones. Could adding some resistance help out? All I can say is that I would probably do some mad scientist work, and see if that took me anywhere. Apogees are an obvious example of the designer really going all out, with absolutely no concern for the amplifier manufacturer. Thus, you need brute force solid state of the nth degree.
In the end, you may just end up where you began, so keep the original crossovers intact for referece. But, wherever your journey takes you, you still may end up ahead of all the rest of us with your fabulous speakers.
Good luck,
Joe
