This question is aimed to TRUE Elec Engineers, not fuse or wire directionality believers.

OOPS(never heard them referred to, with that acronym)!

Less than one minute ago, I concluded an experiment. In series, I connected a .1uF Jupiter, copper foil/paper/wax capacitor, a Quart, 8 Ohm tweeter and the negative, of my Fluke multimeter(set to 2 VDC). Touching the multimeter’s positive lead to the + end of a 1.5V, C cell battery and the capacitor’s open lead, to the battery’s - end, results in a momentary(1-2 sec), 1.5VDC reading on my multimeter. Reversing the polarity, results in the same, every time. If there is full DC getting through, long enough for my multimeter’s digital display to recognize and register it, It’s difficult for me to believe, that(perhaps) 80VDC, from a toasted SS amp’s outputs, wouldn’t fry a tweeter. Color me skeptical.

Anyone, living under the delusion that the NON-POLARIZED FILTER CAPS, used to block low frequencies from tweeters, WON’T PASS DC, needs to try measuring the voltage of a battery in series with one. That’s assuming you own a multimeter(or voltmeter).

Interesting followup- I just tried the same experiment, but substituted a ClarityCap ESA, 33uF, 250V cap and got a constant 1.45VDC reading, with either polarity. 

Battery anatomy/specs aside, the driver was working, prior to being connected to a 33uF, non-polarized film cap and a C cell. It was reading 6 Ohms(correct nominal, according to the tweeter’s label), before it opened up. Imagine what(perhaps) 80VDC, would do. The tweeter had been sitting on a shelf, for the past 20+ years. My son blew the other, clipping his amp into a pair of Quart One bookshelf speakers, back when he was a kid. Not a big loss(at all), but- thanks for your condolences .

Same results, for a moment. BUT, now the tweeter’s blown(it literally/audibly, "popped"). Trying to read, across the tweeter’s terminals, wasn’t any more, "meaningful"(since I already knew DC voltage would pass), BUT- decidedly more EXPENSIVE! Explaining the results is easy(ie: non-polarized film capacitors, WILL pass DC).

My apologies to the OP, for the departure from their basic query.

Conducting an experiment(yesterday) with a Speakerlab W1048P, 10" woofer(two layer, 2", 10mm overhang voice coil, 200W power handling), with only the C cell and 33uF Clarity ESA, produced a pronounced pop, at the moment the battery was connected(iow: a DC voltage spike). The first time I tried that with the tweeter(cap/C cell/tweeter/in series), the spike was sufficient to take out the tweeter. Removing the battery and discharging the cap into the driver, produced the same transient(rhetorical). As far as the amount of juice, provided by a C cell: without the capacitor, it was sufficient to hold the woofer at it’s full, linear(10mm, measured) excursion, as long as I kept it connected(also- rhetorical, but- the tweeter couldn’t take it, even through the cap). Wish I hadn’t sold my O-Scope. I could measure the transient’s actual time/voltage(if frogs had wings....). I have little doubt, variations in capacitor values(uF/VDC), would alter the results(at least regarding duration).

Regarding the woofer’s excursion; That’s what happened, with 1.5 VDC. Infer what you like. I suppose, were I to dig through my shoppe’s old inventory, found a 4 or 5uF cap, and an 8 Ohm resistor, then bought another O-Scope, I could provide more details, regarding exactly what’s occurring, regarding the DC voltage spike, through the cap(s). The facts are: the tweeter blew and there’s a distinct pop, from the woofer, when connected to a C cell, through a non-polarized capacitor. That indicates there’s a transient, being passed to the driver. As I mentioned at the outset, these are experiments that can easily be done, by anyone really interested. Anyone that does conduct such: I’d like to hear their results/conclusions(particularly, if you own/use an O-Scope).

"OK- you didn’t damage the tweeter with a 0.1uf cap, but you did with a 33uf cap. The 33 uf cap allows for much lower bandwidth of information through the tweeter, which in most cases only handle a few watts. My surmise is the 33uf cap made for too much excursion." There is no, "much lower bandwidth of information", that could possibly proceed from a battery. Also- that tweeter blew when the multimeter was taken out of series. I never tried it, using the .01uF, without the multimeter. I may just dig a tweeter out of my old inventory, to(perhaps) sacrifice. I had a box of EV Interface A & B, paper coned tweeters, for doing EV’s warranty work(REAL cheap), back in the early Eighties).  That'll have to wait until the temps in my garage, get above 0 Degrees(F).  The premise that I’ve been testing, is that NO DC voltage would get past a non-polarized capacitor. At least, that’s what’s been proffered in this thread.

1) "Finally, although it’s more of an academic point than one having practical significance, if a large DC voltage is suddenly applied to a capacitor, and a large current briefly flows corresponding to C(dv/dt), the nearly instantaneous change in voltage means that spectral components are present at non-zero frequencies, at and near that instant. Which by definition means that the voltage is not DC, at and near that instant." 2) "The tweeter was damaged because there was significant inrush current to charge that particular cap. Once charged no more current flows. That is how an exponential charging curve works." That explains why transients both blew the tweeter and caused the pops from the woofer, when the discharged capacitor and battery were reconnected. Whatever was passed through the nonpolarized capacitor ("spectral components"/DCV/Dark Energy?), it blew the tweeter and created sound(however briefly) through the woofer. Again, I wish I had a scope, with which to better record the duration and amplitude of the spike.   Apparently, no one out there with a scope, cares enough to perform such a simple experiment, to either confirm or disprove my results.

"That’s because there is no need. I’ve got plenty of scopes but its academic." Sorry to say, that’s what I expected. Regarding, "Ask any speaker designer." I made my living, in Orlando/Winter Park, FL, repairing/reconing speakers, designing/building and selling pro and home audio speaker systems, back in the 70s and early 80s. The ’Great Winter Park Sinkhole’, pretty much put me out of business. It ate part of my property(along with all utilities) and three neighboring businesses, almost bought it as well(two did, not that any of that matters). Happy listening! https://www.orlandosentinel.com/news/nationworld/os-fla360-pictures-winter-park-sinkhole-20121113-ph...

Can’t say as I had. Then again, I’d expect whatever voltage was getting into the system, to follow the path of least resistance. Even with an inductor(as opposed to a cap), the woofer would be the first victim and(if playing music at the moment) the caps in the crossover, would already be charged/blocking. My home systems(even the 8", 2 way) were all warranted to handle 356 Watts(peak program). Far as clipping, I twisted the cathodes of a couple Zeners(voltage chosen according to the particular tweeter) together, stuck them in a TO-39 heatsink, and hot-melt-glued them on the crossover board, across the tweeter leads. The only condition in the warranty: If the glue was melted out of the sink, they only got the first tweeter free, along with a verbal treatise on amplifier clipping(sold a few Haflers that way). Only ever had to warranty one pair. Replaced LOTS of other brands’ tweeters for the many college students, in that area and installed/sold lots of those little protection devices. As a result, I regained my love/passion for college parties. What sucked was having just put down $30K, on a $130K building(land contract), one month b4 the sinkhole. You’d have to remember the economy, and how hard it was to get a commercial loan, back in 1980. NO banks were doing it(in Florida, anyway) and $30K was a lot more money, back then. I was always in the Black, b4 that. Again: Sorry to the OP, for the hijacking! https://www.electronicsurplus.com/thermalloy-aavid-2228b-hardware-heatsink-for-to-39-or-to-5-compone...