These speakers tend to be listed on Ebay and Facebook marketing and Craiglist from time to time. They use to sell for around $179 a pair. I found them local for $30 a pair. They are not a wimp. The cabinets are about 3/4 in thick, and stuffed good and weigh a little over 10 lbs each -- the 5-1/4 in woofer has a poly-resin frame and the magnet is big, and seems to be polypropylene with aluminum color. The tweeter is a 1 inch teteron dome tweeter with a neodymium magnet. The crossover seems to be 2nd order and said to be 1850 hz.
They sound surprisingly nice/decent with tight controlled bass, with good detail and a decent soundstage. they tend to lack some refinement and depth. However, I will take them over the former Infinity Primus speakers and Pioneer BS-22 and Polk RTi4 -- and I would not pay full price for the Sony Core over these speakers. For sure a serious good deal for my $30.
Here is a slideshow
https://www.audiocircle.com/index.php?action=gallery;area=slideshow;album=27319;start=182328;size=xlarge