By: Doug Blackburn I remember KLH from reading ad-free underground high-end audio magazines in the 1970s (primarily Stereophile and The Absolute Sound that were small self-published booklet-style magazines back then with no advertising, intentionally). KLH produced a flat-panel electrostatic loudspeaker in the early 1960s that set the audiophile community abuzz with its performance relative to other loudspeakers available at that time.…