Digi-Wave receiver 400 series. Batteries and earphones not

Ideal Use Cases

The Williams AV Digi-Wave DLR 400 ALK is designed for listeners who need to hear a presenter wirelessly through a compatible Digi-Wave system. Its documented operating modes include intercom, interpretation, and other modes, making it applicable wherever those system functions are required. Compatibility with the DLT 400 and DLT 300 lets the receiver integrate with those listed Digi-Wave units rather than operate as a stand-alone audio source.

With a stated range of up to 900 ft (274 m), depending upon environmental conditions, it can support listeners across areas where cable-free reception is important. The receiver’s 3.5 mm TRRS jack delivers mono output to headphones, earphones, or a neckloop, so the listening device can be matched to the user’s needs. At 1.7 oz (47 g) without batteries and 2.36″ W x 3.54″ H x 0.63″ D, it provides a compact footprint for individual use.

Why Choose This Model

Its key benefit is the frequency-hopping algorithm, which allows users to securely listen to presenter audio wirelessly on the 2.4 GHz ISM band. FSK modulation and an internal antenna are integrated into the receiver. The LCD gives immediate visibility into battery level, RSSI, and group/channel number, bringing the status information needed for day-to-day operation onto the unit itself.

It uses two AAA alkaline batteries and is rated for up to 30 hours with BAT 010-2 alkaline disposable batteries. When no RF signal arrives from compatible devices for five minutes, Auto Sleep Mode activates to save power. This combination supports extended use while reducing unnecessary battery drain when the associated system is inactive.

Installation and Integration

Integration is centered on three documented elements: alkaline battery power, the Digi-Wave wireless link, and the headphone output. Install two AAA alkaline batteries, use the receiver with a compatible DLT 400 or DLT 300, and connect headphones, earphones, or a neckloop to the 3.5 mm TRRS jack. The output is mono, with a maximum output of 27 mW at 32 ohms.

The LCD can then be used to monitor battery level, RSSI, and group/channel number. Because the antenna is internal, no external antenna connection is specified. System placement should account for the stated environmental dependence of the 900 ft maximum range and the operating temperature range of 14° to 113°F (-10° to 45°C).

Performance Highlights

Audio performance is specified by mode. At the -3 dB level, intercom mode covers 100 to 7,300 Hz, while interpretation and other modes cover 100 to 11,200 Hz. The receiver is rated at 74 dB SNR, A-weighted, and 0.1% typical THD. These figures provide concrete references for signal-to-noise performance, distortion, and usable frequency range.

Wireless operation uses the 2.4 GHz ISM band with FSK modulation and frequency hopping. Range is rated up to 900 ft (274 m), with actual reach dependent on environmental conditions. The black ABS plastic case houses the internal antenna, LCD, battery power, and audio connection in a body measuring 2.36″ W x 3.54″ H x 0.63″ D.

What Makes It Different

Unlike a generic audio receiver, the DLR 400 ALK is specified around Digi-Wave compatibility and presenter listening. It identifies group/channel status and received signal strength on the LCD, accepts three categories of listening accessory through one TRRS output, and includes automatic sleep behavior tied to the absence of RF from compatible devices. The combination of frequency hopping, compact physical size, and alkaline operation defines this configuration.

Regulatory and environmental approvals listed for the receiver are FCC, Industry Canada, RoHS 3, CE, WEEE, RCM, ANATEL, KC, Giteki. A two-year warranty covers component failure and manufacturing defects, subject to the full warranty details on the manufacturer’s website.

Final Assessment

The DLR 400 ALK is a focused choice for a Digi-Wave setup using DLT 400 or DLT 300 units. It combines secure wireless presenter listening, up to 900 ft stated range, a status LCD, and up to 30 hours of alkaline battery life. Its mono 3.5 mm output supports headphones, earphones, or neckloops, while the documented audio, power-saving, and operating specifications provide clear parameters for system planning.