i still have my Hollywood Sound Labs HSL12SE i bought new in 1996. i ran 4 of them for a while, split them up, and loaned a pair to a buddy who had them stolen. i still use the other 2 in my garage.
great subs, JL W4 replicas, basically. (note dual 6 ohm coils).
these were made for groups of 3 or 6. you can get to 1 ohm or 4 ohms with 3 subs or 0.5 ohms or 2 ohms with 6 subs. this would be a great match for an older HCCA 225 amp (stable to 0.5 ohms)
they sound great sealed. just like a JL from the same era.