Microphone Positioning

Microphones with various polar patterns can be used in vocal recording techniques. Consider recording a choral group or vocal ensemble. Having the vocalists circle around an omnidirectional mic allows well trained singers to perform as they would live: creating a blend of voices by changing their individual singing levels and timbres. Two cardioid mics, positioned back to back could be used for this same application. An omnidirectional mic may be used for a single vocalist as well.

If the singer is in a room with ambience and reverb that add to the desired effect, the omnidirectional mic will capture the room sound as well as the singer's direct voice. By changing the distance of the vocalist to the microphone, you can adjust the balance of the direct voice to the ambience.

The closer the vocalist is to the mic, the more direct sound is picked up relative to the ambience. The standard vocal recording environment usually captures the voice only. This typically requires isolation and the use of a unidirectional mic. Isolation can be achieved with baffles surrounding the vocalist like a shell” or some other method of reducing reflected sound from the room. Remember even a music stand can cause reflections back to the mic. The axis of the microphone should usually be pointed somewhere between the nose and mouth to pick up the complete sound of the voice.

Though the mic is usually directly in front of the singer's mouth, a slightly off-axis placement may help to avoid explosive sounds from breath blasts or certain consonant sounds such as p”, b”, d”, or t”. Placing the mic even further off-axis, or the use of an accessory pop filter, may be necessary to fully eliminate this problem. While many vocals are recorded professionally in an isolation booth with a cardioid condenser microphone, other methods of vocal recording are practiced.

For instance, a rock band's singers may be uncomfortable in the isolated environment described earlier. They may be used to singing in a loud environment with a monitor loudspeaker as the reference. This is a typical performance situation and forces them to sing louder and push their voices in order to hear themselves. This is a difficult situation to recreate with headphones. A technique that has been used successfully in this situation is to bring the singers into the control room to perform. This would be especially convenient for project studios that exist in only one room.