Of all the equipment used in the creation, and reproduction of music, nothing is as overlooked, misunderstood and improperly used as the microphone. Concert-goers are often impressed by the size of the sound system, the stage lighting, costumes, fancy guitars and such, but little if any attention is paid to the device without which the concert would be impossible: the microphone.

When rock 'n' roll was spawned some twenty-odd years ago, much of the equipment was like the music: simple. But as rock 'n' roll grew into 'Rock,' the demands made on instruments became much greater, so the technology of the equipment has been and continues to be refined and improved. As specific musical situations have arisen > engineers have designed microphones to accurately reproduce the sound of specific instruments in specific situations. Some microphones are designed for more general applications, some for very specific uses, but not microphone is suitable for all types of sound recording, reproduction, or broadcast.

For example, the AKG D-10000E is a very popular microphone that has switchable equalization built into the mike itself. A three-position switch controls the bass and midrange frequency response of the mike and enables the D-10000E to be effectively used in 'close miking' or distant miking situations. The tight cardiod ('heartshaped') pickup pattern of the D-10000E and its ability to reproduce high sound pressure levels without distortion make the microphone useful in a number of situations.

On the other hand, another microphone, such as the D-12E (also by AKG Acoustics) is designed with a more specific purpose in mind. This mike has a large diaphragm and a strong proximity effect; that is, when the mike is 'close-talked,' bass response is increased. Thus the D-12E is recommended for kick-drums, double bass and other bass percussion.

Still another good mike, the AKG D-190E, has the bass response 'rolled off' (deemphasized) to compensate for the proximity effect. Also, the D-190E has a boosted mid-high frequency response. For these reasons, the mike is very useful for home recording situations, since it works well with a variety of instruments. Matched pairs of these mikes are available in high or low impedance. As good as the D-190E is, it is not the ideal microphone for use on the road, because it is somewhat more delicate than other mikes, such as the Shure SM-58, for example.

One new model that incorporates both ruggedness, field servicability and a broad frequency response is the D-330BT from AKG. The outer grille is made of stainless steel mesh to absorb shock and impact. Underneath the grille is a layer of polyurethane foam that serves as a wind screen and a pop-filter, and beneath that there is a safety basket, which is a superstructure that protects the transducer system module from head-on impact damage. The superstructure also keeps the grille assembly from becoming deformed when the mike is dropped.

The capsule body of the D-330BY has a hypercardiod polar pattern (as opposed to a cardiod pattern such as is found in the D-10000E). This gives the mike more directivity and greater rejection of surrounding noise than a cardiod mike, since there is a narrower angle of sensitivity. This.pattern also provides more gain before feedback, meaning that the mike would be good for a vocalist in a rock band because it would have a high output and a strong resistance ;to other noise or musical sounds.

The D-330BT has something akin to an electric guitar component built into it; that is, a hum-bucking coil that eliminates unwanted interference from house lighting and other electrical equipment. In addition to the hum eliminator, there is also a handling noise rejector, which utilizes a second transducer, .wired out of phase with the primary transducer, which serves to cancel electro-mechanical noise caused by handling. The result is an additional noise reduction of 30 decibels at 100 Hz (cycles per second).

The D-330BT has a patented elastomer suspension system that 'floats' the microphone's inner module,3so that when the microphone is accidentally dropped, the suspension system compresses in a braking action to protect the module from impact damage. Another elastomer suspension is located beneath the transducer module, which not only adds to the stability and isolation of the entire module assembly, but also supports the internal female receptable at the base of the transducer module.

The entire transducer module, which includes the primary capsule, the humbucking coil, the secondary noise-cancelling capsule and an equalizer switch, can be removed from the housing by simply unscrewing the grille assembly clamping ring. This means that the mike can easily be serviced in the field, which is a primary consideration of sound companies that do sound'reinforcement in concert situations.

Like the D-100E, the D-330BT has two recessed equalization switches built into the mike that allow the user to shape the sound in the desired fashion according to how the mike is being used. The upper three-way switch controls two levels of increased 'presence' as well as a 'flat' response. The lower switch controls bass response, so that the performer can control the proximity effect by rolling off the bass response. Thus, low-frequency feedback or excessive boominess can be avoided at the microphone. A filter system keeps the impedance and sensitivity constant, thereby enabling the signal-to-noise ratios to be maintained.

While the D-330BT is by no means offered up to the public as the 'ultimate' mike (there is no such ultimate among mikes), it is nevertheless a remarkably well-designed instrument, one that should not be overlooked by serious microphone users and buyers.