// TEST r2p – Netspire™ Network Amplifier Module Netspire™ Network Amplifier Module
Passengers using smartphones at station as the train comes in

Netspire™ Network Amplifier Module

The NetSpire™ NAM2i is an intelligent, network enabled amplifier. The device receives network digital audio and provides output to speakers using two integrated 12 watt Class D amplifiers, digital signal processing, and digital voice announcement.

The NetSpire™ NAM2i devices are housed in IP66 rated enclosures suitable for installation in harsh, outdoor, and rolling stock environments, where immunity from dust, water and physical deformation is required.

The NAM2i units integrate seamlessly with the NetSpire system and allow audio zones to be created anywhere a connection to the network is available. Each speaker is connected to an independent audio channel, and can be assigned to separate announcement zones or grouped in the same zone. The NAM2i can be configured to perform a different series of audio processing functions on each of the output channels. The 24bit DSP can perform the following configurable chains of audio processing functions on each channel:

  • Delay
  • Gain adjustments
  • Dynamic Range Compression & Expansion
  • Power Limiting
  • Parametric Frequency Equalisation

The NAM2i units also have a single balanced audio input which can be used to connect an Ambient Noise Sensing Microphone (ANC). The microphone is used to measure the ambient noise conditions of zone and adjust the volume of announcements automatically to compensate.

The NAM2i housing is IP66 rated, and encompassess the cable terminations on the NAM2i carrier bracket.


  • Two network digital audio inputs and outputs
  • Two Class D Amplifier output channels
  • One balanced analogue audio input
  • Two isolated digital inputs
  • One isolated digital output
  • Web configuration, diagnostics and logging
  • Integrated DSP processing
  • Integrated Digital Voice Announcement
  • Emergency Audio Ready (EN60849)
Example System Topologies


  • Integrated termination of cabling with IP66 protection
  • Supports software selectable gain for microphone analogue input
  • 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 two channels of 12W low impedance audio
  • Supports speaker health monitoring and can detect and report a fault in a single speaker
  • Supports one isolated digital output under software control
  • Supports two isolated digital inputs which can be configured to change audio routes or initiate recorded announcements.
  • 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.