I happened across a pair of JBL K151 speakers loaded in custom cabinets and used as "bass dumps" or subwoofers in a P.A. I bought the pair of cabs thinking they were EV loaded like the rest of the P.A. Turns out this pair has these JBLs in it. The JBL site directed me to a "vintage" site when I searched the model number. In there is a 1976 sales brochure for the K series speaker line. In that brochure, it lists the primary purpose for the K151 300watt driver as being bass guitar and organ. Everything I've read about this speaker has been really complementary. Does anybody know anything about the JBL K151 18" speaker?