Adolfo,
Not ever auditioned any of Nora Jones recordings, I can only comment on the other two artist, and their recorded material. All of the EW&F recordings are very muted compared to today's better recorded material. Even Sade, though better than EW&F, are muffled as well from early recording equipment.
At a minimum, take Diana Krall for a spin before making drastic cable changes. Close-miked recordings by Shirley Horn and Patricia Barber will also put a grin on your face.