Passengers using smartphones at station as the train comes in

Netspire™ Network Audio Controller




The NetSpire™ Network Audio Controller (NAC) is an intelligent, network enabled digital audio controller with integrated power amplifiers, digital signal processing, digital voice announcement, analogue input and output and digital I/O control signals. The device supports a large number of integrated functions greating reducing installation cost and system footprint.


  • Four network digital audio inputs and outputs
  • Up-to eight Class D Amplifier output channels
  • Four balanced analogue audio inputs and outputs
  • Eight isolated digital inputs and outputs
  • Web configuration, diagnostics and logging
  • Integrated DSP processing
  • Integrated Digital Voice Announcement
  • Emergency Audio Ready (EN60849)

Example System Footprint Comparison




  • Supports software selectable gain for line and microphone analogue inputs
  • Supports Phantom, Avionic and Electret microphone power
  • Supports microphone capsule health monitoring using current sense technology
  • Supports up-to 48kHz 24 bit PCM for network digital audio. Lower bit rate and compressed codecs are also supported
  • Supports up-to eight channels of 100V Audio, Low impedance Audio and Loop Current Amplifier modules
  • Supports speaker bus health monitoring and can detect and reports a fault in a single speaker on a bus
  • Supports audio frequency inductive loop health monitoring and fault reporting
  • Supports eight isolated digital outputs under software control
  • Supports eight isolated digital inputs which can be configured to change audio routes or initiate recorded announcements. Can be paired with microphone inputs for "push-to-talk" applications.
  • Supports ambient noise compensation (ANC)
  • Supports extensive DSP capabilities on each channel, including per channel gain, delay, power limiting, dynamic range compression and parametric equalisation.
  • Supports pre-recorded Digital Voice Announcement (DVA) functions with flash storage for over 90 minutes of recorded announcements and 3000 individual announcement segments stored in the voice dictionary.
  • Supports internal clock for scheduling announcements or background music. Synchronisation of clock using NTP.
  • Supports in-built attention, test and alarm tones
  • Supports network configuration and monitoring via a standard web browser, or the NetSpire suite of administration, monitoring and control software.