Directional microphone array system with DSP and recording

Portable processing and recording for microphone arrays

FALENA integrates audio processing and recording in a 180 × 130 × 40 mm unit. Connected to a suitable microphone array, it captures speech from a separate monitoring position. The stated maximum listening distance is approximately 150–300 m (490–984 ft), depending on array configuration, source level and environmental noise.

Two inputs operate simultaneously, each with its own filtering and automatic level control. A sunlight-readable 4.3-inch color capacitive touchscreen gives the operator local access to audio settings and system parameters.

DSP controls for challenging acoustic conditions

Processing options include automatic level control (ALC), a programmable noise gate, and band-pass, low-pass, high-pass and notch filters. Up to five filters can be cascaded at once.

Presets address interference associated with power lines and electromagnetic fields, traffic noise and broadband urban noise. The operator can adjust processing to the available audio, rather than relying on a single fixed filter setting.

48-microphone analog array and digital beam steering

Photo A shows an analog array with 48 microphones. Their signals are summed to improve directionality and signal-to-noise performance. The panel is physically aimed toward the source.

Photo B shows a digital configuration with four panels of 20 microphones each: 80 capsules across a 40 × 32 cm assembly. A low-power FPGA processes the individual signals to form and steer the listening beam electronically within the configuration’s operating capabilities.

FALENA versions are available with or without the cabling and software needed for electronic beam control. Digital signal transfer reduces susceptibility to interference associated with low-level analog connections.

Memory-card recording and local control

Audio is stored on a memory card. The listed recording capacity is approximately 45 hours per card for one channel of uncompressed audio.

The internal 12 V rechargeable lithium-ion battery provides up to 24 hours under ideal conditions with power saving enabled. Actual runtime varies with use. Local operation uses the touchscreen. Browser-based network control and remote self-test are described as planned features; the supplied documentation states that the remote-control option has not yet been implemented.