Off the wall variant:
I'm thinking old school GUITAR AMP ...sincerely
What if you go in WholeHog, and find a couple medium sized BASS GUITAR AMPs, say having 10 inch speaker,
like a high school orchestra Bass player might exhibit.
Two of those, each are really really close, or maybe 3 inches taller/wider, it's more a cosmetic match left and right.
Tweeters, you could use ¢ 75 cent piezo elements schotch taped to whatever. But if that's at work, not living room, hmmm : skip the tweeter part, just buy a candy bar, if that's like, forklifts passing by the aisle etc