Allen & Heath AH-M-AHM-64-AEC-A Acoustic Echo Cancellation (AEC) Module for AHM-64

Product Overview

The Allen & Heath AH-M-AHM-64-AEC-A is an acoustic echo cancellation module engineered specifically for the AHM-64 audio matrix processor, providing 12 channels of AEC processing for teleconference, videoconference, and unified communications applications in corporate boardrooms, conference rooms, and commercial meeting spaces. Acoustic echo cancellation is the foundational signal processing technology that prevents microphone-captured audio from feeding back into far-end callers — a requirement in any AV system where a loudspeaker and microphone operate in the same room simultaneously during a call. Installed as an internal module within the AHM-64, the AEC card processes channels in real time using a 150ms FIR adaptive filter without adding external hardware to the signal chain.

Product Description

The AEC module operates by inserting into AHM-64 channel inserts — one insert is placed in the far-end input channel (the audio arriving from the remote caller) and a second insert in the near-end input channel (the local microphone). This dual-channel insert method allows the module to continuously model the acoustic characteristics of the room, track changes in the environment, and cancel the reference signal (the far-end audio played through the room’s loudspeakers) from the near-end microphone feed before it is transmitted back to the far-end participant.

Beyond core AEC, the module includes Far-End Automatic Gain Control to normalize varying far-end signal levels, Non-Linear Processing (NLP) to attenuate residual echo that falls below the adaptive filter’s cancellation threshold, Background Noise Reduction to suppress HVAC and room noise, and Near-End Gating to prevent transmission of ambient noise during silence. Speech-Shaped Comfort Noise generation maintains a natural listening experience for far-end participants by replacing silence with low-level noise that signals an active, open connection rather than a dropped call. Combined, these processing stages deliver a full professional-grade far-end audio experience suitable for boardroom and executive conference environments.

Key Features

• 12 Channels of Acoustic Echo Cancellation — Sufficient for conference rooms with multiple ceiling or table microphones connected to the AHM-64
• 150ms FIR Adaptive Filter — Long filter tail handles highly reverberant conference rooms and accommodates varying acoustic environments
• Far-End Automatic Gain Control — Normalizes far-end caller levels regardless of the remote participant’s microphone or system gain
• Non-Linear Processing (NLP) — Attenuates residual echo below the adaptive filter’s cancellation floor for clean near-end audio
• Background Noise Reduction — Reduces HVAC, projector fan, and ambient room noise from the transmitted signal
• Near-End Gating — Suppresses microphone transmission during periods of near-end silence to reduce background noise on the call
• Speech-Shaped Comfort Noise — Maintains a natural call experience by generating low-level noise during near-end silence rather than abrupt silence
• Sound Reinforcement Output — Dedicated output for local voice reinforcement applications within the same room

Typical Applications

• Corporate boardroom teleconference and videoconference AV systems
• Executive conference room unified communications integration
• Government and legal conference room AV infrastructure
• University and academic collaborative learning room AV
• Commercial meeting space AV managed services installations
• AHM-64-based multi-room corporate AV systems with UC integration

Technical Specifications

Frequently Asked Questions

What is acoustic echo cancellation and why is it needed in a conference room?

Acoustic echo cancellation (AEC) removes the audio played through the room’s loudspeakers from the signal captured by the microphones before it is transmitted to the far end. Without AEC, remote participants hear their own voice echoed back through the room, making calls difficult to follow.

How many microphone channels does the AHM-64-AEC-A support?

The module provides 12 channels of AEC, which is sufficient for most conference rooms with ceiling microphone arrays or multiple table microphone units connected to the AHM-64.

How is the AEC module installed in the AHM-64?

The module is assigned using channel inserts within the AHM-64’s routing matrix. One insert is placed in the far-end input channel and another in the near-end microphone channel. No external wiring beyond standard AHM-64 routing is required.

Does this module work with the AHM-32?

No. This module is designed specifically for the AHM-64. For the AHM-32, the AH-M-AHM-32-AEC-A is the correct module.

What is the benefit of the 150ms FIR adaptive filter?

A longer adaptive filter tail allows the AEC to cancel echoes in reverberant rooms where reflected sound may arrive at the microphone well after the original loudspeaker output. 150ms is sufficient for most professionally treated and moderately reverberant conference rooms.

Is the AEC processing introduced by this module audible as latency?

The processing latency introduced is within the acceptable range for natural conversation and does not produce perceptible delay from the user’s perspective in a normally configured system.