Schoeps DSP4KFM360
4 Signal DSP Processor, A/D-D/A Converters

DSP4KFM360

The DSP-4KFM360 is a signal processor for the Schoeps KFM 360 SET or KFM 360 stereo microphone. The processor derives the four “corner” channels (L, R, LS, RS) from the microphone signals. A center channel signal is obtained from the two front signals. An additional output channel is provided which carries only the frequencies below 70 Hz. To avoid perceiving the presence of the rear loudspeakers one can lower the level of their signals, delay them and/or set an upper limit on their frequency response.

The front stereo image width is adjustable, and the directional patterns of the front-facing and rear-facing pairs of “virtual microphones” can be chosen independently of one another. The processor unit offers both analog and digital inputs for the microphone signals. In addition to providing gain, it offers high-frequency compensation for the pressure transducers as well as low-frequency compensation for the figure-8s. As with M/S recording, matrixing can be performed during post-production. All matrixing in the DSP-4 is performed in the digital domain.

The front and rear channels result from the sum (front) and difference (rear) of the omnidirectional and figure-8 microphones on each side respectively. The four resulting “virtual microphones” which this process creates will seem to be aimed forward and backward, as the figure-8s are. At higher frequencies, however, they will seem to be aimed further outward. Their directional pattern can be varied anywhere from omnidirectional to cardioid to figure-8; the pattern of the two rear-facing virtual microphones can be different from that of the two forward-facing ones. Altering the directional patterns alters the sound as well, in ways that are not possible with ordinary equalizers. This permits a flexible means of adapting to a recording situation – to the acoustic conditions in the recording space – and this can even be done during post-production if the unprocessed microphone signals are recorded. The signals from the four “virtual microphones“ comprise a type of surround reproduction which is valid in its own terms but lacks the center channel and low-frequency channel of the standard 5.1 approach, so these additional facilities are provided by the digital signal processor.

Our Part #  DSP4KFM360