Williams AV FM 557-12 – Dual FM and Wi-Fi Hearing Assistance, 12 Receivers

Product Overview

The Williams AV FM 557-12 is a dual FM and Wi-Fi hearing assistance system that gives mid-size venues a direct path to ADA-compliant assistive listening. The FM+ T55 transmitter broadcasts on the 72 MHz FM band for the twelve included PPA R37N body-pack receivers while simultaneously streaming the same audio over the venue's Wi-Fi network for smartphone listeners. For facilities replacing aging FM 457 hardware or adding hearing assistance to a sanctuary, theater, or hearing room, this package delivers transmitter, receivers, earphones, neckloops, and ADA signage in one order.

Product Description

The T55 transmitter occupies half a rack space and replaced the earlier T45 with substantially more capability: DSP audio processing with selectable compression and filtering, an OLED display for menu-driven setup, a hosted web page for remote configuration, and Telnet control over Ethernet for tie-in to room control systems. Audio sources connect through a combination XLR/1/4-inch input supporting balanced or unbalanced microphone or line-level signals with selectable phantom power — typically a spare DSP or mixer output in a commercial installation. Each of the twelve PPA R37N receivers offers seek-button access to 17 wideband channels between 72.1 and 75.9 MHz, channel lock to hold the house frequency, and a 3.5 mm output that drives the included EAR 022 surround earphones or the three NKL 001 neckloops supplied for telecoil hearing aid users. Receivers run approximately 50 hours on the included AA alkaline batteries and accept NiMH rechargeables with optional drop-in chargers. Because the FM broadcast supports unlimited listeners, the system scales simply by adding receivers — there is no license, channel pairing, or head-end change involved. This standard package leaves antenna selection and rack mounting to the integrator; FCC rules require professional installation with an approved FCC 15.203-compliant antenna such as the ANT 005. For a version with the antenna, charger, batteries, and rack kit bundled in, see the FM 557-12 PRO package, or browse our full Williams AV collection.

Key Features

• FM and Wi-Fi from One Chassis — The T55 transmitter feeds dedicated FM receivers and smartphone listeners on the venue network simultaneously, with no second transmitter required.
• Twelve Body-Pack Receivers — PPA R37N receivers with EAR 022 surround earphones provide the hardware ADA guidelines expect mid-size venues to stock.
• 457-System Replacement Path — The FM+ platform directly replaces legacy Williams FM 457 systems while preserving the familiar 72 MHz receiver band.
• Telecoil Neckloops — Three NKL 001 neckloops couple audio magnetically to hearing aids and cochlear implants with telecoils.
• Seek-Button Tuning with Channel Lock — Receivers access 17 wideband channels and can be locked to the assigned frequency for the duration of an event.
• 50-Hour Receiver Runtime — Two AA alkaline batteries, included, power each receiver for roughly 50 hours of listening.
• DSP Speech Processing — Selectable compression and high/low-pass filtering at the transmitter improve intelligibility for hearing-impaired listeners.
• Network Configuration and Control — A hosted web page and Telnet over Ethernet enable remote setup, monitoring, and control-system integration.
• ADA Plaque Included — The IDP 008 wall sign informs visitors that assistive listening devices are available on request.

Typical Applications

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

Technical Specifications

Frequently Asked Questions

Is this a direct replacement for an FM 457 system?

Yes. Williams AV positioned the FM+ 557 family as the replacement for its 457 systems. It keeps 72 MHz-band FM operation — so the receiver experience is familiar — and adds Wi-Fi streaming for smartphone listeners at close to the cost of the older FM-only hardware.

What do I still need to complete the installation?

An FCC 15.203-compliant antenna (such as the ANT 005) and, if rack mounting, an RPK 005 or RPK 006 panel kit. The FCC requires professional installation. If you prefer those items bundled with a charger and rechargeable batteries, choose the FM 557-12 PRO package instead.

How do smartphone users hear the broadcast?

The transmitter connects to the venue's existing Wi-Fi network and streams the program audio to listeners' phones. It does not generate its own wireless network, so functioning venue Wi-Fi must be available.

Can hearing aid wearers use this system without earphones?

Yes. The three included NKL 001 neckloops plug into any R37N receiver and couple the audio magnetically to telecoil-equipped hearing aids and cochlear implants.

How many listeners can the system support?

The FM broadcast is unlimited — every receiver in range on the assigned channel hears the feed, and Wi-Fi listeners add no RF load. Buy additional PPA R37N receivers as needed.

What warranty covers the equipment?

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