The d:facto's microphone head can be used on the DPA wired handle, and can also be unscrewed for mounting onto some wireless microphone systems, offering a high degree of flexibility. The option of wired and wireless modes, combined with DPA's proven technology, has resulted in a live performance vocal mic that encapsulates flexibility and unsurpassed sound quality.
DPA Microphones A/S is the leading Danish Professional Audio manufacturer of high quality condenser microphones and microphone solutions for professional applications in studio, broadcast, theatre, video/film and sound reinforcement environments. All DPA microphones and components are manufactured at the company's purpose-built factory in Denmark.
A double-button carbon microphone has a push-pull action that cancels second harmonics. A good microphone with level response from 60 Hz to nearly 10 kHz, except for some wiggles of a few dB near the upper limit, was created. The sensitivity, however, was only about -47 dB, much less than that of a telephone receiver, in microphones optimized for good fidelity. By this time electronic amplification was available, so low output was not a drawback. Such microphones were used in recording and broadcasting in the early days, and gave very good service.
The outstanding disadvantage of the carbon microphone is noise, the so-called "carbon hiss," that could not be eliminated, though it could be reduced by careful preparation of the granules. This noise is inherent in the source of variable resistance, which was the surface properties of the carbon granules. Carbon by itself, even in bulk, exhibits 1/f (pink) noise, and this was exacerbated in the granules. The noise can be represented as a random voltage or current generator in series with the signal generator, in the usual way for noise analysis. The carbon granules could be damaged, and even fused together, by unusually high currents, such as those produced by inductive kicks. If the hermetic seal of the button was damaged, moisture could cause the granules to pack. The resistance of the microphone would decrease in that case, and it would become much less sensitive.
|Number of Microphones||Positioning|
|One||Use an "overhead"|
|Two||Kick drum and overhead|
|Three||Kick drum, snare, and overhead|
|Four||Kick drum, snare, and two overheads|