>>2942119
I don't think the diagram is wrong, it's a pretty simple single layer PCB. But maybe I fucked up somewhere, pic related.
Don't inductors kill high frequencies? The 180 μH inductor on this board would work for a ~2500 Hz passover frequency if used in series as a low pass filter. I didn't consider that it'd short out frequencies lower than that in this circuit, that makes sense I suppose. Didn't see anything like that in the high pass filter designs I googled oddly enough.

>>2942128
I just tried that, good idea. The reverse image search tools come up with small, round, brown components, which doesn't really narrow it down much. I was hoping the symbol would mean something to someone, I couldn't find it in any electronic component symbol list sadly.
At the end of the day a resettable fuse and a thermistor would mostly play the same role in this diagram, I think? Inrush current protection sounds important if that's a risk, but I haven't seen that in any other high pass filter diagrams.
>though I doubt it would do much unless your tweeter is drawing a fair bit of power.
They're 3 Ω speakers and I'm just using an aftermarket android radio without additional amplifier, so it probably wouldn't be necessary. Some posts I found on similar things said this is a ceramic capacitor. I don't see how this would make any sense, but I don't know shit about this stuff, so I'm unsure. I suppose it would at least have the capacitance printed on it if that were the case.

Thanks for the feedback.