I had a pair of those exact speakers that I pulled the tweeters from to replace the blown ones in some other speakers. The KLHs sat around for a while, tweeterless, and I was getting ready to throw them out, but before I did, I played some bass tracks through the woofers to finish 'em. This wasn't too long ago. I feel bad about it now (they were a Christmas present when I was about 8 or 9--I'm obviously not very old), but I needed the tweeters because PE didn't sell anything with the same dimensions and I already had better-sounding speakers. I was going to keep the woofers for a DIY project or something, but I couldn't think of what I wanted to do with them. Also, they had foam surrounds, and I didn't want to put effort into DIY speakers only to have them dry rot a few years later. The only reason I feel bad is because, like I said, they were a Christmas present with my little tube amp kit that I still have.
Edit: The speakers at the top of the stack in my avatar are the KLHs. I attached the old piezo horns from my Peaveys to them, but that only made them sound terrible because of the sensitivity mismatch.