Sennheiser MKH 416 The MKH Story - Page 7

The MKH Story The bidirectional MKH 30 (figure-of-eight) The omnidirectional microphone as a pure pressure transducer represents one end of the directivity scale. The other end is occupied by the bidirectional characteristic of a pure pressure-gradient microphone. Therefore the development of a bidirectional microphone seemed reasonable. Moreover, the push-pull transducer was predestined for this application due to its symmetrical design. At that time the frequency responses of many bidirectional microphones showed deficiencies at low and high frequencies. Contrary to these microphones the MKH 30 (launched in 1987) was designed as a full studio microphone with a flat and extended frequency response. Therefore the MKH 30 is also very suitable as a spot microphone, which facilitates a high degree of acoustic separation between adjacent sound sources. Due to its frequency independent directional characteristics and tonal neutrality it allows a higher degree of reinforcement than other microphone types. In addition, as both front and rear lobes are identical, the MKH 30 is the ideal side microphone in an MS recording rig. The super-cardioid MKH 50 A super-cardioid was the next microphone type in the schedule. Compared to cardioids, super-cardioids usually exhibit less bass response. The MKH 50 (launched in 1988) breaks with this tradition as it features the same extended bass response as the MKH 40. The directional properties at high frequencies are also well-balanced. The reason for this is the affinity of the super-cardioid pattern to the directional characteristics due to the pressure build-up effect. All microphones are prone to this effect at high frequencies, nearly independent of the rated directivity at lower frequencies. Pressure build-up occurs if the sound waves at high frequencies are no longer bent around, but are more or less reflected by, the microphone, which then acts as an acoustic obstacle. On-axis sound can cause a pressure boost of up to 10 dB. This changes the pressure profile at the transducer so that the directional properties are dominated by the pressure build-up effect. The sophisticated acoustic design of the MKH 50 provides a smooth crossover from the super-cardioid to the pressure build-up characteristic. The interference tube (shotgun) microphones MKH 60 and MKH 70 The next microphones were designed to accompany the interference tube (shotgun) microphones MKH 416 and MKH 816. The new shotguns MKH 60 (short) and MKH 70 (long) (both launched in 1991) were not intended to replace the older types, but rather for extending the shotgun line. So the MKH 60 was designed slightly longer than the MKH 416, and the MKH 70 a little shorter than the MKH 816. The MKH 816 was too long and too heavy in many cases, so most users preferred the MKH 70. The MKH 60 became a companion of the MKH 416 and was used if more directivity was required. It can also be used as a spot microphone for high-grade music recording at longer microphone distances. The weight of the new shotgun microphones was minimised without compromising the mechanical stability. Both microphones featured switches for pre-attenuation, bass roll-off and treble boost. Page 7