For those of you that know REL, you know the S series is their high end line and the S5 is the big boy. These are audiophile / hi-fidelity grade subs and retail for $2500 each. They are not the SHO version.
The 12in long-excursion front driver has a large surround and 550W of Class D amp to drive it. Underneath, floor-firing, is a thin 12in disc of high-tech carbon fiber, also on a roll suspension. This is passive and offers the S5 benefits over ported or sealed designs.
Optional REL's Longbow wireless transmitter will pair and receive the bass signal as a composite of both high-level from the speaker feed and the low-level with lossless transmission.
The S5 has direct-connection sockets on the back too, adjusted by crossover knob but separate gain controls for both high- and low-level inputs. You also get a 10m cable with a Speakon plug which is the best feature of these subs. It allows you to pair them directly with a speaker to pick up the low level bass that most speakers can't reproduce.
Matching pair of these and they are both in really great condition. The subs themselves are almost perfect. The grills are missing some of the standoffs, so I don't put them on any more. I do have them if you want to try to fix the pegs.
This price is for one unit, will sell separately or as a pair. I do have one of the original boxes and manual. Local pickup only as these are too heavy to ship.