I dunno if that's what's up, Bill. I wouldn't expect the driver to start sounding worse after just a few hours with moderate power. I suppose it might have had some foreign object get inside; That would be more likely in my mind to make a change of sound character. Then again, that wouldn't change DC resistance. And I can't imagine debris getting in there in a home hifi environment. So this is an oddball thing, I think.The DE200 sounds a lot like the PSD2002 to me. They don't sound exactly the same, of course, but similar. The DE250 sounds more like the old drivers with aluminum diaphragms, but with much more extension than aluminum drivers, like a titanium 'phragm has. Sort of a cross between them, smoother than titanium, more extension perhaps. Not as much extension as beryllium, but nice.