For the size and type, not a bad sound. I kept the stock reflex box of my '95 325is intact, these are in the package tray of the rear window. These stock boxes are ported, an opening of about 1/2 x 2, I shoved some cotton-based batting material inside of them except around the port wave zone and the low-end response is impressive. I am only pushing about 30 watts as I am using the stock Harmon-Kardon amp. Just don't push this speaker, it's not designed for it.
Pros: For the cost, it's a good upgrade to the factory ones, although, after 17 years, the factory ones were worn out.
Cons: The only caveat, (if you can call it that) is that to put these in the stock boxes, I had to snip off 2 of the 4 mounting tabs. But, with them being serrated, they are designed that way. They were also a tad bit smaller in circumference then factory, so I sealed the gap with silicon. As it turned out, doing that forces the free air out the port - making for lower-end!