Soon after the formation of KEF, Raymond Cooke re-established his previous relationship with the BBC and KEF took on the exclusive manufacture of the LS5/1A monitor system, a system to which KEF’s meticulous approach to production engineering was well suited. The monitor utilised a Goodmans C129/15pr 15” woofer and two Celestion HF1300 tweeters and was designed for studio broadcast monitoring. The system stayed in production for more than ten years and was a useful benchmark for KEF’s own designs.
KEF also supplied the LS5/5 (including manufacturing the bextrene coned 12” bass and 8” midrange units) the LS3, LS5/2A, LS3/4 and LS5/6. In 1973, the KEF designed Reference Series Model 5/1AC, an active version of the LS5/1A, went into production and found application in many of the new independent radio stations of the time.