If I can add to @tomthiel ’s exceellent summary ot the CS 2’s; on numerous occsasions different individuals at Thiel Audio have commented that the CS 2’s were the most robust, reliable speakers Thiel has ever made.
As a personal note, while the CS 2’s are perhaps the easiest from a technical perspective Thiel’s to drive, they do benefit from quality amplification. The ported bass can be a bit soft and perhaps due to this there can be something of a sonic upward tilt, coupled with a somewhat forward presentation. New they were a real value; at their current used prices make these speakers an absolute terrific bargain. Some users might have been temepted to overdrive them with underpowered amplification. The double sided baffle tape might make baffle removal a bit difficult, but it is most prudent to examine the drivers before purchasing to make sure they are original and in good shape. I’ve seen many where unscrupulous sellers try pass off cheap fixes as originals. I don’t mean to discourage potential buyers, just the opposite. If the seller refuses to offer photos of the drivers, or if you see them connected to cheap recievers: be wary.
Coupled to an amplifier with tight bass, a sweet top end, that isn’t too forward in presentation (not typicaly a cheap, easy find) one can put together a fairly inexpensive system that shoots way above it’s weight class. Despite their really inexpensive used costs, they can really benefit from better upstream gear.
I’m not sure there’s a better used speaker available at their current asking prices. Highly recommened!