Williams AV IMA-840 Spectrum 100W Infrared Wireless Microphone Receiver Amplifier

Williams AV IMA-840 Spectrum Receiver Amplifier

The IMA-840 Spectrum is Williams AV's most powerful infrared classroom audio system, engineered for large classrooms, boardrooms, and conference areas where more than four speakers are needed. Its dual wireless infrared microphone receivers support simultaneous use of a hands-free Sapphire pendant and a pass-around IRH-35 handheld microphone (sold separately), ensuring every participant is heard clearly. Integrated overhead speakers deliver consistent, high-quality sound for in-person and hybrid learning environments.

This 100W digital hybrid Class D amplifier powers up to eight 8-ohm classroom speakers and includes four line-level inputs for auxiliary, computer, DVD, or conference sources. EchoGuard technology synchronizes classroom audio with video conferencing applications while preventing remote audio from looping back into the conference feed. Assistive Listening System (ALS) outputs with rear-panel gain control ensure accessibility, and paging support with muting and pass-through keeps announcements clear.

Designed for safety, control, and convenience, the Spectrum supports teacher security alerts via the Sapphire microphone, fire alarm muting, RS-232 control for all input levels, and Digital Feedback Guard to reduce audio feedback. Additional features include low-power standby mode, drop-in USB microphone charging, and flexible mounting options, making the IMA-840 Spectrum the ideal solution for large-scale classrooms, hybrid learning, and professional presentation environments.

• 100W digital hybrid Class D amplifier, powers up to eight 8-ohm classroom speakers
• Dual infrared wireless microphone receivers
• EchoGuard video conference synchronization prevents audio feedback loops
• Four line-level inputs: auxiliary, computer, DVD, and conference sources
• Assistive Listening System (ALS) output with rear-panel gain control
• Paging support with page muting and pass-through to classroom speakers and ALS output
• Teacher security alert function via wireless microphone
• Fire alarm connection mutes all audio sources
• RS-232 control for volume up, down, and mute via third-party devices
• Digital Feedback Guard (DFG) to reduce audio feedback
• Remote teacher control over line inputs via the Sapphire microphone
• Low-power standby mode (automatic and manual)
• Drop-in USB microphone charging (5VDC)
• Suitable for classrooms, boardrooms, and large conference areas
• Supports in-person and hybrid learning environments

Spec Sheet

Manual

Quick Start Guide