Williams AV FM 558 PRO – FM+ Listening System, 4 Receivers

Product Overview

The Williams AV FM 558 PRO is a small-venue assistive listening system that bundles the FM+ C dual FM and Wi-Fi transmitter, four PPA R38N receivers, and the essential installation accessories into one package. It is built for courtrooms, classrooms, boardrooms, and small houses of worship that need ADA-compliant hearing assistance, language interpretation, or audio description without sourcing antennas, chargers, and signage separately. The transmitter broadcasts simultaneously over FM and the venue's Wi-Fi network, so listeners can use a supplied receiver or their own smartphone with the WaveCAST app.

Product Description

The easy-to-install FM+ C transmitter delivers real-time FM audio across 17 selectable wideband channels (72.1–75.9 MHz) while streaming the same program to Wi-Fi listeners. Its DSP engine offers selectable compression and high-pass/low-pass filtering for clear, intelligible speech, and a combination XLR/1/4-inch TRS input with selectable phantom power accepts the room's microphone or line-level feed. The half-rack chassis mounts in a standard 19-inch rack using the included RPK 005 panel kit, and the 3.12-inch OLED display, hosted web page, and third-party room control compatibility cover local and remote configuration.

Each of the four R38N handheld receivers carries a bright 1-inch OLED screen for menu-based channel selection, a channel lock to keep loaner units on the house frequency, and a detachable belt clip. Two BAT KT6 two-bay chargers and NiMH rechargeable batteries keep the receivers ready for roughly 32 hours per charge — or swap in AA alkalines for up to 50 hours. Four EAR 022 surround earphones serve general listeners, while two NKL 001 neckloops support guests with telecoil hearing aids. The ANT 005 remote coaxial antenna provides FM coverage up to 1,000 feet, and the IDP 008 ADA wall plaque announces assistive listening availability at the entrance.

Need Dante network audio integration? The FM 558 PRO D adds a Dante-enabled transmitter to the identical kit. Larger venues should look at the 12-receiver FM 558-12 PRO.

Key Features

• Dual FM and Wi-Fi Transmission — A single half-rack transmitter serves dedicated FM receivers and unlimited WaveCAST app listeners on the venue network.
• Four R38N OLED Receivers — Handheld receivers tune across 17 preset wideband frequencies with channel lock and a bright OLED display.
• Turnkey Installation Kit — The ANT 005 antenna, RPK 005 rack panel kit, BAT KT6 chargers, earphones, neckloops, and ADA plaque ship in the box.
• Telecoil Support — Included NKL 001 neckloops couple audio inductively to telecoil hearing aids and cochlear implants.
• DSP Audio Processing — Selectable compression and filter controls optimize the feed for speech intelligibility in assistive listening applications.
• Versatile Use Cases — The same hardware supports hearing assistance, language interpretation, and audio description channels.
• Rechargeable Power Included — Two-bay drop-in chargers and NiMH batteries deliver about 32 hours of receiver runtime per charge.
• Network Remote Management — The hosted web page over Ethernet enables remote monitoring and third-party room control integration.

Typical Applications

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

Technical Specifications

Frequently Asked Questions

What audio source does the transmitter need?

A microphone or line-level feed from the room's audio system, connected to the rear XLR/TRS combo input. Selectable phantom power supports condenser microphones for rooms without a mixer.

How do smartphone users listen?

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

Does this package meet ADA requirements for small venues?

It provides receivers, telecoil neckloops, and the required availability signage. Verify the minimum receiver count for your seating capacity against ADA assistive listening tables; additional receivers can be added at any time.

Is professional installation required?

Yes. FCC rules require professional installation with approved FCC 15.203 compliant antennas, such as the included ANT 005 remote coaxial antenna.

Can the system expand as the venue grows?

Yes. Add PPA R38N receivers as needed; FM listener capacity on the selected channel is unlimited, and the Wi-Fi stream already supports unlimited app users.

What is the warranty?

The transmitter is covered for 2 years parts and labor; R38N receivers carry the Lifetime PLUS Limited Warranty, with 90 days on most accessories.