I did this when I blew the tweeters in my JBL L88's in the '70's. Removed the tweeters and sent them to JBL for repair/replacement (which they did with no charge, even though I was not the original owner of the speakers. Wow!) Anyway, I had a month or two with no tweeters. So since my Pioneer receiver had two sets of speaker outs, I connected a pair of no-name speakers from my first department store brand stereo, and placed them on top of the big JBL's. Problem solved.
Bring on the criticism...
So I was swapping out my Maxx 1's for 2's a few weeks ago and yesterday it occurred to me since I can't bi-amp like I have always wanted I would bi-speaker. Two Maxx's side by each running off my FPB450's. I guess I never really considered myself an audiophile and this must confirm it, but I really like the stage it's throwing.