Hello, guys! Anybody knows of filtering technique of Rock vocals in 60's..70's+? I mean vocals of Beatles, Blondie, Quatro, ZZTop, LedZep, early AC/DC and similar. What types of filters were used: LPF/HPF/.., secret comb filtering, phase related filtering,..? Wikipedia tells that Mr. Martin used an 'advanced filtering technique' of vocal recording. What is it? It seems Rock vocals were recorded in very narrow range of 800Hz-1.5K and heavely compressed. And early mixers had just 1, 2, 3 knobs of HPF or LPF! Any info, please.