If you want it to perform even reasonably well, you can't just replace it with any driver, even another sub driver. Sub design is more complicated than that. But, what brand and model is it?
Yow.
It stopped rattling about half way through. Did you change something?
BTW, that sub sounds massively fried. As in, the voice coil of the driver is cooked. Hard to say without more info if there's anything to do about it, or if it's even worth fixing.