Replacement capacitors exploding

Upon closer examination, the old capacitors say NP and the new ones say BP.

I’ve been searching for non-polarized capacitors and I have found three different sites where the item description says non-polarized capacitor and then the photo is of a capacitor with BP written on it, not NP What is that about?

I’m mulling over what I’ve learned, here and elsewhere. I had 17 of these boxes in various stages of disrepair, a handful of them worked sort of OK.

So the first thing I noticed was these blown capacitors, so I posted, but I’ve had a lot of other work to do, assessing blown and not stock drivers, repairing jack plates, and cleaning compression diaphragms and painting duratex etc.

i’m not sure all of them had drivers that met the stock ohm rating, that may have been a factor, although so many of them were blown I have a hard time believing that accounts for everything.

My gut tells me that the bipolar capacitors, while rated at the same voltage, simply couldn’t take the same degree of abuse that the non-polar ones did.
I think I’m going to biAmping a lot of them and rebuild a few of them with really nice crossover parts for when I’m doing smaller gigs and just need a simple set up.

Some are definitely 4 ohm (stock). I have three generations of these so it's hard to know what is or is not stock. Even some of the Klipsch K-43 drivers seem different. And some for sure aren't stock.