Williams AV FM 558-12 PRO D – Dante FM+ System, 12 Receivers

Product Overview

The Williams AV FM 558-12 PRO D is a mid-size venue assistive listening system that pairs a Dante-enabled FM+ transmitter with 12 PPA R38N receivers and professional installation accessories. Designed for council chambers, courtrooms, lecture halls, and mid-size worship spaces with networked audio infrastructure, it broadcasts ADA-compliant hearing assistance over FM (72.1–75.9 MHz) and Wi-Fi simultaneously. The Dante input takes a channel straight from the room's DSP or console over the audio network, removing the need for an analog tie line to the assistive listening rack.

Product Description

The Dante-enabled FM+ transmitter at the core of this package occupies half a rack unit and mounts with the included RPK 005 rack panel kit. In addition to its Dante network audio input, it provides a combination XLR/1/4-inch TRS jack for balanced or unbalanced microphone or line-level sources with selectable phantom power, so the system can be commissioned even before the Dante routing is finalized. Onboard DSP applies selectable compression and high-pass/low-pass filtering to maximize speech intelligibility, and the 3.12-inch OLED display, hosted web page, and third-party room control compatibility give integrators multiple paths for configuration and monitoring.

The 12 PPA R38N receivers each carry a 1-inch OLED display with menu-based access to all 17 wideband channels and a channel lock function that keeps loaner units on the house frequency. Included two-bay chargers with NiMH rechargeable batteries keep the fleet ready, while EAR 022 surround earphones and NKL 001 neckloops cover listeners with and without telecoil hearing aids. The ANT 005 remote coaxial antenna extends FM coverage up to 1,000 feet, and the IDP 008 ADA wall plaque posts the required assistive listening notice at the room entrance. Listeners beyond the 12 hardware receivers can join over Wi-Fi using the WaveCAST app, so capacity is never capped by receiver count.

For venues without Dante infrastructure, the FM 558-12 PRO analog version delivers the same package with a standard FM+ transmitter. See the full range in the Williams AV collection.

Key Features

• Dante Audio Network Input — The transmitter subscribes to a Dante channel from the room DSP or console, simplifying integration in networked AV systems.
• Dual FM and Wi-Fi Output — One unit feeds the 12 included FM receivers and an unlimited number of WaveCAST app listeners simultaneously.
• 12 R38N OLED Receivers — Body-pack receivers offer 17 wideband channels, channel lock, and up to 50 hours of battery life for managed distribution.
• Complete PRO Accessory Kit — Remote coaxial antenna, rack panel kit, chargers with rechargeable batteries, neckloops, earphones, and ADA signage are all included.
• Telecoil Hearing Aid Support — NKL 001 neckloops couple receiver audio magnetically to telecoil-equipped hearing aids and cochlear implants.
• DSP Speech Optimization — Selectable compression and filtering shape the feed for clear speech in assistive listening and interpretation applications.
• Remote Web Management — The hosted web interface over Ethernet supports remote monitoring and integration with third-party room control platforms.
• 1,000 ft FM Coverage — The included ANT 005 antenna provides FM range up to 1,000 feet for full coverage of mid-size and large rooms.

Typical Applications

• Government space
• House of worship
• Auditorium
• Training room
• Commercial meeting space
• Multi-purpose room
• Boardroom

Technical Specifications

Frequently Asked Questions

How is the Dante input configured?

The transmitter appears as a Dante receive device on the audio network. Route a channel to it in Dante Controller from any Dante-enabled source, such as a DSP, console, or matrix processor.

Can I use the analog input and Dante on the same unit?

The transmitter provides both a Dante network input and an XLR/TRS analog combo input, giving integrators flexibility in how the program feed is delivered during and after commissioning.

Does this package satisfy ADA assistive listening requirements?

It supplies FM receivers, neckloops for hearing aid telecoil coupling, and the IDP 008 availability plaque. Confirm the required receiver count for your venue's seating capacity against ADA guidelines.

Is professional installation required?

Yes. FCC rules require the transmitter to be professionally installed and operated with approved FCC 15.203 compliant antennas, such as the included ANT 005.

Can audience members listen on their phones?

Yes. The transmitter streams the same audio over the venue's Wi-Fi network to the WaveCAST app, with no limit on the number of app listeners.

What warranty coverage is included?

The transmitter carries a 2-year parts and labor warranty; the R38N receivers carry Williams AV's Lifetime PLUS Limited Warranty, with 90 days on most accessories.