I replaced the damaged speakers with 2 pairs of new Logitech 10 watt speakers, for a total output of 20 watts. I enclosed the whole bundle with 2 protective metal baskets for cages, but I went for strength over stealth, so it's pretty unsightly
The new setup is definitely louder than before.
The hoodrats were very emboldened by their 48 hour respite from the music, so here you can see their numbers have multiplied. Also they are sharing a whole watermelon like something out of a bad meme.
These photos are from maybe 30 minutes after the music broadcast was restored.
The attached video is from a few hours later, so it's possible they were dispersed by the music.
They are still listening to "Thoroughly Modern Millie" on loop. I'm beginning to grow weary of that song myself, so I may change it later this week.
To prepare for installing more broadcast units to achieve full coverage, I bought another 3.5mm audio splitter and another pair of desktop speakers, this one being 16 watts, so if I doubled it with an identical pair, it could be 32 watts total. It's got a spherical shape, which is really different from the rectangular box speakers I've been using for this project, so I will need to figure out a new way to suspend and support these spherical speakers.
Fortunately I was able to salvage one pair from the damaged 6 watt speakers by combining the working elements from both. I'm going to use this salvaged pair for the next broadcast unit I install, maybe combine it with the new spherical speakers.