What is a good bookshelf

I wonder if my oldest son blew tweeters when I was on vacation. I have owned these since 2000. I havent really used the stereo much until I moved to new residence. I wonder if that maybe the cause?
I know the bottom end would have to be placement. But upper end I am wondering.

Interesting idea-call parts Express. Sometimes they have identical replacement drivers. Very inexpensive and might be worth a try. easy to replace and it might be fun!

One that doesn't sag under the weight?

Try Sequerra. It's a Sealed Monitor Speakers Met 7.7

if your amp is up to it, Usher BE-718 will be a very big upgrade.