I once rebuilt a pair of Infinity SM 152's
100db sensitive... 350w capable.
They look like this:

You NEED to recable these internally because the original wire is
so bad it sucks!
But when you recable it, say with Taralabs omni or the likes, then it sings!!!
It does not have a soundstage mind you...
But this baby has got rock potential and ZERO earpiercing!!! Easy load!
Can play LOUD!!!
Get a pair, and then recable it (You must!!!) and you've got yourself a cheapo rockspeaker!!
And I'd just like to add, I placed the speaker on mattress foam plugs after the rebuild.
They should depress 1/3, then they are correctly sized.
The result?
Slam clarity and a Bass articulation that to this day I seldom hear in speakers!
My brothers pair. He since sold them, they are large boxes!
The 15" subdrivers have a tiny magnet, but if you modify this speaker with some common sense..
It's capable of some serious sound! Again, it does NOT image... it can't!
This is not high-end, just a good pop/rock partyspeaker... that's what you get here...

You can pick up a mint pair for around 350-450$ Then all you gotta do is modify it.
You could build a better filter, recable it and repack inside, put in some braces and stuff.
This is a gem!
Imperial