I always liked the sound of the 1980s Time Windows, but I was a
poor college student at the time so I could only afford a set of
QEDs.

I recently picked up a nice pair of Time Windows on eBay, but
found something unexpected. My QEDs are wrapped in grill FOAM,
but my Time Windows are wrapped in grill CLOTH. Looking around on
eBay again, I see that some Time Windows have cloth, but others
have foam like my QEDs. Also, investigating a little deeper, I
find that some Time Windows use Philips tweeters and others,
including the pair that I just bought, use Vifa.

Anybody know the history behind the changes?

Thanks,
Greg