Q: “What are the functional differences between cardiod, hypercardioid and supercardioid microphones in a live situation?”
A: Unidirectional microphones are available with several variations of the cardioid pattern. Two of these are the supercardioid and hypercardioid. Both polar patterns offer narrower front pickup angles than the cardioid (115 degrees for the supercardioid and 105 degrees for the hypercardioid) and also greater rejection of ambient sound. While the cardioid is least sensitive at the rear (180 degrees off-axis), the least sensitive direction is at 125 degrees for the supercardioid and 110 degrees for the hypercardioid. When placed properly they can provide more “focused” pickup and less room ambience than the cardioid pattern, but they have less rejection at the rear: -12 dB for the supercardioid and only -6 dB for the hypercardioid. When choosing a microphone for live performance a key factor you should consider is the specifics of the operating environment. Where are the stage monitors placed? Are there any other loud instruments (guitar rig, drums, brass section) nearby, and where are they positioned? What sort of mic technique does the vocalist have? If he or she doesn’t stay on top of the mic then you may need one with a wider pattern such as a cardioid. Also important to consider is the off-axis frequency response. Most directional microphones get progressively more omni directional at lower frequencies. There’s been other Tech Tips written on this topic in the past so if you want more information just do a search of the archives.