Post-6863-1128264237 ThumbHere are two great how-tos from the Sony mini disc forums “How to build a high quality stereo / binaural miniature microphone Required parts: – 2 omnidirectional miniature electret microphone capsules (get the best ones you can find / afford – your selection will have a major influence on the sound quality) – 3.5 mm stereo connector with cable, preferrably shielded – a few inches of heat shrinkable tubing, slightly larger diameter than the capsules” Link.