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

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).

@rodman99999
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.

Caps charge along something called an exponential curve. At the beginning of the curve a lot of current flows and not so much at the top of the curve.

The **amount** of current that can flow has a lot to do with the value of the cap! 33uf is a lot more than 0.1uf and so the additional current was enough to do the tweeter in.

IOW that fact that you were able to damage the tweeter does not say anything about how a tweeter would pan out in a properly designed crossover. If we do the math:


F = 1/C x R x 2Pi

Where F is frequency
C is capacitance and
R is resistance

To make this formula easier to use, because Farads are a lot of capacitance, we will use Microfarads (uf); so we can replace the 1 with 1,000,000 and that will give us the Frequency in cycles per second. So:
804Hz = 1,000,000/33 x 6 x 6.28


With a 0.1uf cap, we get 265KHz. IOW, a **lot** more energy was allowed to pass through the tweeter with the larger cap. Most tweeters need to be crossed over pretty high- 5KHz is common and for that a 5uf cap would suit. See if you can damage the tweeter with your battery and a 5uf cap. You can’t, because the cap allows only about 1/6 as much energy before current stops flowing.


This is the tip of the iceberg here. But the bottom line is that tweeters survive output transistors shorting in the power amp quite easily- unless the crossover cap isn’t rated to handle the resulting DC voltage and is thus damaged by it (speaker manufactures don’t like to ship boxes around any more than they have to so they make sure to put in crossover caps with a high enough voltage rating).


To put myself through engineering school I worked in several consumer electronics service shops and repaired many speakers damaged by shorted output transistors. IOW, I replaced **woofers**. When the amplifier clips but is otherwise damaged, that’s when tweeters fail, as the clipping generates harmonics that the crossover can’t block. The tweeter is damaged by the great power of the distortion harmonics. The solution in most cases where this is seen is to get either a more powerful solid state amp or get a tube amp (which makes less higher ordered harmonics).

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.