Williams AV FM T55C-00 – FM+ Dual FM and Wi-Fi Assistive Listening Transmitter

Product Overview

The Williams AV FM T55C-00 is an FM+ assistive listening system transmitter that broadcasts FM and Wi-Fi audio simultaneously from a single input source, making it a flexible choice for ADA compliance in auditoriums, houses of worship, and commercial meeting spaces. Listeners can use a traditional 72–76 MHz FM receiver from the venue or stream real-time audio to their own smartphone through the free WaveCAST Receiver app for iOS and Android. Built on a professional DSP audio platform with Telnet control over Ethernet, the FM+ C integrates cleanly into commercial AV systems managed by third-party room control processors.

Product Description

The FM+ C is the first transmitter of its kind to offer an FM broadcast and a Wi-Fi audio broadcast from one input. Whether deployed for assistive listening, language interpretation, or audio description, this dual-broadcast design means venues no longer have to choose between providing an FM assistive listening system or a Wi-Fi streaming system — one half-rack transmitter covers both. The FM side operates on 17 selectable wideband channels between 72.1 and 75.9 MHz and is compatible with all current and legacy Williams Sound FM receivers in the 72–76 MHz band, with a transmission range of up to 1,000 feet using the ANT 005 coaxial antenna.

For AV integrators, the FM T55C is built for installed systems. It supports Telnet commands over its rear-panel Ethernet port, so third-party room control systems can manage power, audio gain, channel selection, DSP presets, and more. Configuration is available three ways: the front-panel 3.12-inch OLED display, a hosted web interface, or Telnet over the network. The professional DSP platform includes selectable presets optimized for voice, music, or hearing assistance, plus adjustable high-pass and low-pass filters and compression options for greater speech intelligibility.

The combination XLR/1/4-inch TRS input accepts balanced or unbalanced line-level or microphone signals with selectable phantom power, so the transmitter connects directly to a house mixer or DSP output. The chassis occupies one EIA rack unit at half-rack width; one or two units mount in a single 19-inch rack space with the optional RPK 005 or RPK 006 rack mount kits. The system ships with an ANT 025 antenna, TFP 062 power supply, and WLC 004 line cord. Note that the FM+ C joins the venue's existing Wi-Fi network for streaming — it does not generate its own network — and the FCC requires professional installation with approved FCC 15.203-compliant antennas.

If your design calls for Dante network audio input, see the FM T55CD-00 Dante-equipped model, or browse the full Williams AV assistive listening collection for compatible receivers and antennas.

Key Features

• Dual FM and Wi-Fi Broadcast — Transmits a 72–76 MHz FM signal and a Wi-Fi audio stream simultaneously from a single input source, serving both dedicated receivers and personal smartphones.
• WaveCAST App Streaming — Listeners connect to the venue Wi-Fi and select channel and volume in the free WaveCAST Receiver app for iOS and Android for a discreet bring-your-own-device experience.
• Professional DSP Audio Platform — Voice, music, and hearing-assist presets plus adjustable filters and 1:1, 1.5:1, or 2:1 compression deliver clear, intelligible audio to every listener.
• Telnet Room Control Integration — AV professionals can control power, gain, channel, and DSP preset from third-party control systems over the RJ-45 Ethernet port.
• Legacy Receiver Compatibility — Works with all current and legacy Williams Sound FM receivers operating in the 72–76 MHz assistive listening band.
• Long Transmission Range — Covers up to 1,000 feet with the ANT 005 coaxial antenna, suitable for large auditoriums and worship spaces.
• Flexible Audio Input — Combination 3-pin XLR and 1/4-inch TRS jack accepts balanced or unbalanced line or microphone signals with selectable phantom power.
• Rack-Mount Ready — Half-rack, 1RU chassis mounts singly or in pairs in a standard 19-inch rack with optional RPK 005/RPK 006 kits.
• Three Management Interfaces — Configure via the front-panel OLED display, hosted web page, or Telnet commands over Ethernet.
• RF Sleep Mode — Automatically stops transmitting after 30 minutes or 4 hours of silence to reduce power use, waking instantly when audio returns.

Typical Applications

• Auditorium assistive listening systems
• House of worship hearing assistance
• Government space ADA compliance
• Conference room and commercial meeting space language interpretation
• Multi-purpose room and all-hands room audio description
• Training room hearing assistance

Technical Specifications

Frequently Asked Questions

Is the FM T55C compatible with existing Williams Sound FM receivers?

Yes. The FM+ C works with all current and legacy Williams Sound FM receivers operating in the 72–76 MHz wideband range, including the FM R37 and FM R38, so venues can keep their existing receiver inventory.

Does the FM+ C provide its own Wi-Fi network for streaming?

No. The transmitter connects to the installation site's existing Wi-Fi network, which must be in place before the Wi-Fi audio stream can be used. The FM broadcast operates independently of the network.

Can I integrate the FM T55C with a Crestron, Extron, or other room control system?

Yes. The transmitter accepts Telnet commands over its Ethernet port, including power, audio gain, channel selection, and DSP preset changes, so it can be monitored and controlled from third-party room control processors.

Does the FM T55C require professional installation?

The FCC requires this device to be used with approved, FCC 15.203-compliant antennas and to be professionally installed. Refer to the Williams AV antenna selection guide for compliant antennas such as the ANT 005, ANT 024, and ANT 025.

What is the difference between the FM T55C and FM T55CD?

The FM T55CD adds an RJ-45 Dante network audio input for facilities running a Dante audio network. All other transmitter functions are identical between the two models.

What warranty does Williams AV provide on this transmitter?

The FM T55C carries a 2-year warranty against component failure and manufacturing defects. Creation Networks can assist with warranty coordination and system design support.