Williams AV FM 557 PRO D – Dante FM+ PRO System, 4 R37 Receivers

Product Overview

The Williams AV FM 557 PRO D is the entry point to Dante-enabled assistive listening: a complete FM+ PRO system pairing the T55 D dual FM and Wi-Fi transmitter with four PPA R37N receivers and professional installation accessories. The Dante input lets the transmitter take program audio directly from the venue's audio network, while listeners choose between the supplied body-pack FM receivers and Wi-Fi streaming on their own smartphones. For courtrooms, boardrooms, training rooms, and smaller worship spaces designing around networked audio, this package covers ADA hearing assistance in a single SKU.

Product Description

Professional AV installers favor this system because the T55 D transmitter behaves like modern networked equipment rather than a standalone RF box. Its Dante port subscribes to an audio flow from the house DSP or console; its OLED display, hosted web page, and Telnet-over-Ethernet command set handle configuration, monitoring, and third-party control integration; and its half-rack chassis mounts in a standard 19-inch rack using the included RPK 005 panel kit. An analog combination XLR/1/4-inch input with selectable phantom power remains available for venues feeding a microphone or analog line source. The transmitter's DSP applies selectable compression and high-pass/low-pass filtering so the broadcast stays intelligible for hearing-impaired listeners, and it operates on 17 selectable wideband channels between 72.1 and 75.9 MHz. The four PPA R37N receivers tune those same channels with a seek button, run roughly 32 hours per charge on the included rechargeable batteries managed by two BAT KT6 two-bay chargers, and pair with EAR 022 surround earphones; two NKL 001 neckloops support telecoil hearing aid users. The ANT 005 remote coaxial antenna delivers transmission range up to 1,000 feet — far beyond the needs of a single room, which makes the package suitable for overflow and multi-space coverage. FCC rules require professional installation with a compliant antenna. Venues with bigger audiences can scale to the FM 557-12 PRO D twelve-receiver package, and supporting accessories are in the Williams AV collection.

Key Features

• Dante Network Input — The T55 D takes program audio straight off the Dante network, eliminating analog cabling between the DSP and the assistive listening transmitter.
• FM Plus Wi-Fi Streaming — One transmitter serves dedicated FM receivers and smartphone listeners on the venue network simultaneously.
• Four-Receiver Starter Fleet — PPA R37N body-packs with surround earphones cover ADA receiver requirements for smaller assembly spaces, expandable at any time.
• Rechargeable Power Included — Two BAT KT6 two-bay chargers with rechargeable batteries keep all four receivers ready without disposable cells.
• Control System Friendly — Telnet over Ethernet and a hosted web page integrate the transmitter into room control and remote monitoring workflows.
• 17 Selectable Channels — Wideband operation between 72.1 and 75.9 MHz permits multiple systems across a multi-room facility.
• 1,000-Foot Transmission Range — The included ANT 005 remote coaxial antenna covers large areas and adjacent overflow spaces.
• Rack Panel Kit Included — The RPK 005 mounts the half-rack transmitter cleanly in one EIA rack space.
• ADA Compliance Out of the Box — Neckloops for telecoil users and the IDP 008 wall plaque support 2010 ADA hearing assistance guidelines.

Typical Applications

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

Technical Specifications

Frequently Asked Questions

When does the Dante version make sense over the standard FM 557 PRO?

Choose the PRO D when the room's audio already runs on Dante — conference facilities, courtrooms, and worship venues with networked DSPs. The transmitter then needs only a network connection for program audio. Analog-only rooms can use the standard FM 557 PRO.

Is four receivers enough for ADA compliance?

ADA receiver counts scale with seating capacity, and four receivers suit smaller assembly spaces. Because the FM broadcast supports unlimited listeners, additional R37N receivers can be added whenever capacity or attendance grows.

How do the chargers work?

Two BAT KT6 two-bay drop-in chargers are included with rechargeable batteries, charging all four receivers simultaneously. Receivers also accept standard AA alkaline cells for roughly 50 hours of runtime.

Can a control system manage the transmitter?

Yes. The T55 D accepts Telnet commands over its Ethernet port and hosts a configuration web page, so control processors and facility staff can monitor and adjust the system remotely.

What are the installation requirements?

The FCC requires professional installation with an approved FCC 15.203-compliant antenna; the included ANT 005 qualifies. The Wi-Fi streaming feature additionally requires the venue's existing wireless network to be operational.

What warranty coverage is provided?

Two years parts and labor on the transmitter, and a Lifetime PLUS limited warranty on the R37N receivers, excluding earphones, headphones, and batteries.