Microphone Capsule MK 8
When M/S stereo recordings are made, the 0° axis normally faces to the left as viewed from behind the microphone setup. The “8“ engraved on the top of the housing should be aligned on its side so as to appear horizontal, at a precise right angle to the Mid capsule. The microphone should be placed directly above or beneath the “M“ channel microphone, and as close to it as possible.
The inherent qualities of a pure pressure-gradient transducer are readily observed in this capsule type:
- Its sensitivity decreases at low frequencies.
- The directional characteristic is extraordinarily independent of frequency.
- Proximity effect is present.
When an MK 8 is used as a spot microphone, care must be taken to avoid picking up early reflections or unwanted direct sound from its rear, since sound arriving from the back is picked up with full level but reversed in polarity. This could result in partial cancellation of the intended sound, which can lead to comb-filter effects at higher frequencies.
The directivity index of a figure-8 pattern is the same as that of a cardioid; if microphones with these two patterns are placed at the same distance from a sound source, a quantitatively similar balance of direct and reverberant sound would be picked up. In practice such a comparison would be deceptive, however, since a figure-8 does not respond to sound coming from the sides, from above or from beneath its main axis as does a cardioid. The figure-8 has a rear lobe equal in sensitivity to its front lobe, and this exactly makes up the quantitative difference – but in normally reverberant settings, the sound reaching a figure-8's rear lobe will be delayed and dispersed to a considerably greater extent than the reverberant sound energy which a cardioid picks up from its front and sides; the reflected sound will typically be subject to far more high frequency absorption as well. Thus the reverberant sound energy picked up by a figure-8, though theoretically equal in amount, is quite different in character from that which would be picked up by a cardioid in the same position.