Ring 48-75 AC Pro

with 48 channels the most universal array

The Ring 48-75 is a differential array working together with the Multi Channel Data Recorder (mcdRec). The ring on which the microphones are placed is a custom made carbon fiber construction to assure a constant microphone position over long time.

This array can be operated with the mcdRec data recorder.


With this system, high quality acoustic images are acquired within seconds.

The lightweight array-body is designed as slim as possible and is made of carbon fiber. This ensures easy handling and accurate microphone positioning. The wiring of the microphones is enclosed in and protected by the array-body which guarantees the best possible acoustic transparency to measure accurate sound levels. The array design is optimized to provide the highest spatial resolution possible while providing a high depth of field to see all sources in one acoustic map independent of distance (within reason).

The built-in studio microphones have an extremely linear frequency response. All are carefully hand-selected and calibrated to ensure stable sound pressure levels (+/- 0.5 dB). To allow long distances, the array is connected to the mcdRec data recorder via two differential SymBus microphone connector cables (max. 20 m). The array comes with an integrated fixed focus camera, which can be supplied as USB or Ethernet version, delivered in different sensor sizes, resolutions and frame rates. The included high-end Manfrotto tripod allows a set up in almost any measurement environment imaginable. Array and tripod are supplied in a transport case and bag respectively.

Technical Data

  • Carbon array-body diameter: 75 cm
  • Weight: 1.8 kg
  • SymBus microphone connectors via differential conditioning
  • Advanced disturbance tolerant ¼” symmetrically buffered electret pressure receivers (based on Sennheiser microphone capsule 4211)
  • Number of microphones: 48
  • Frequency response of microphones: 20 Hz-20 kHz (± 3 dB)
  • Dynamic range of microphones: 28-130 dB (A-weighted)
  • Acoustic maps from 23-130 dB
  • Max. equivalent sound level: 130 dB
  • Symmetrical output resistance: 100 Ω
  • Recommended measurement distance: 0.5-5 m
  • Recommended mapping frequencies: 400 Hz-20 kHz
  • Single map dynamic: 7-8dB (CBF) using HDR 20-40 dB
  • Connecting Array Cable length to data recorder: 1-20 m
  • Video camera: USB or Ethernet connector; different frame rates and resolutions available
  • Ingress protection code: IP20
  • Operating environment: 0°-45°C, up to 80% r.h.


FileType Size
Ring 48 - 75 AC ProPDF (approx. 480 KB for Acrobat Reader)