https://www.amazon.com/JBL-Studio-550P-10-Inch-Subwoofer/dp/B0071UQ8FS
JBL has it for $600, but the entire Studio line has been on discount for awhile. The normal, recent discounted price on this sub has been $359, so $189 is an eye opener!
Steve81 gives an overview of this sub:
http://forums.audioholics.com/forums/threads/jbl-studio-sub-550p-subwoofer-preview.85768/
The 50lbs is an interesting spec! Where does that weight come from? I checked, the driver frame is cast aluminum, not lead!
I really hope someone here buys one and opens it up to see where they stuck the 3 gallon milk jugs of water to account for the extra lbs!
So, for $756, you can buy a set of 4!
These are 10" sealed subs, they will not get it for those wanting the final word in LFE, by any means, however, if you are a music guy, with anechoic measurement of -3dB at 27Hz, these will offer all of the bass you need after room gain is added!
Also not a bad option to get a couple for HT if you are in an apartment and not wanting your neighbors to go postal on you!
If you want a sub for a larger grand/living room, these will probably not play loud enough if you like to crank it!
As long as these are on sale, I would forget about the typical $400-$500 10" sealed subs and buy two of these instead!