Digi-Wave 400 Series Interpretation System for four languages plus

The Williams AV Digi-Wave 400 Series Interpretation System is a portable, secure wireless listening solution described for five presenters and 50 listeners. This configuration is identified for four languages plus and uses DLT 400 transceivers with DLR 400 ALK receivers. Communication operates in the 2.4 GHz ISM band, while dedicated displays, audio connections, security controls, and battery systems support coordinated presenter-to-listener communication.

Ideal Use Cases

The system is suited to organized interpretation sessions that require multiple presenters and as many as 50 listeners. Published operating specifications cover interpretation, tour, hearing-assistance, and intercom modes, allowing the Digi-Wave platform to address several forms of guided or assisted listening. Its portable format is useful when equipment must be moved between rooms or deployed without a permanently installed listening system.

Why Choose This Model

This model combines substantial listener capacity with encrypted wireless operation. Security features include 87-bit encryption for 300 Series compatibility, 87+128-bit encryption, an encryption PIN, and a settings lock. The specified wireless range reaches up to 900 feet or 274 meters, depending on environmental conditions. Each DLR 400 ALK receiver has an LCD showing battery level, received signal strength, and group or channel number, giving listeners and system operators immediate access to essential status information.

The alkaline receivers use two AAA batteries and provide up to 30 hours of operation with BAT 010-2 alkaline batteries. An automatic sleep mode activates after five minutes without an RF signal from compatible devices. The DLT 400 transceiver uses a built-in 1800 mAh lithium-polymer battery with smart charging and supplies up to 16 hours of talk time per charge when operating with one transmit and one receive channel.

Installation and Integration

Wireless operation uses the 2402–2476 MHz range with FHSS on the 2.4 GHz ISM band. When planning coverage, the stated 900-foot maximum should be treated as environment-dependent. DLR receivers connect to headphones, earphones, or a neckloop through a 3.5 mm TRRS jack providing mono output at up to 27 mW into 32 ohms.

The DLT 400 provides an internal microphone that is disabled when its 3.5 mm microphone jack is engaged. The external microphone input supplies electret bias and offers adjustable gain across a 63 dB range. USB-C supports an adjustable line input and output, while the 3.5 mm TRRS headphone connection delivers 25 mW into 32 ohms. Charging is available through USB-C or two contacts for use with the CHG 412. Listed CCS 054 data specifies a 12-unit capacity, approximately five-hour charging time, individual charge-status indication, and a universal 5 VDC, 6 A adapter.

Performance Highlights

Receiver specifications list a 74 dB A-weighted signal-to-noise ratio and 0.1 percent typical total harmonic distortion. Audio response is 100–7,300 Hz in intercom mode and 100–11,200 Hz in interpretation and other modes. The receiver uses FSK modulation and an internal antenna.

For the DLT 400, audio response is 100–11,500 Hz in interpretation, tour, and hearing-assistance modes with four or fewer microphones; other modes are rated from 100–7,200 Hz. Maximum RF output is 19 dBm. A red LED around the Talk button indicates when talking is enabled, while a bi-color top LED changes between green and red. Side tone is set 6 dB below volume and can be configured to off, low, or high tone variation. The stated operating temperature range is 14 to 113 degrees Fahrenheit, or -10 to 45 degrees Celsius.

What Makes It Different

The Digi-Wave 400 platform brings together encrypted communication, multiple operating modes, portable deployment, and separate power strategies for presenters and listeners. The DLT 400 is compatible with DLR 400 RCH and DLR 400 ALK receivers. It can also work with DLT 300 and DLR 360 devices with some limitations. Listed approvals include CE, FCC, WEEE, RoHS, and CB. The warranty is two years, with cables and the power supply covered for 90 days.

Final Assessment

For interpretation deployments requiring five presenters and 50 listeners, this Digi-Wave 400 configuration provides documented security controls, up to 900 feet of environment-dependent wireless range, status displays, flexible microphone and headphone connections, and long receiver battery life. Its combination of encrypted 2.4 GHz operation, portable hardware, and support for interpretation, tour, hearing-assistance, and intercom modes makes it a focused solution for managed group listening.