Large-area, 48-volt induction loop amplifier with network control

Ideal Use Cases

The Williams AV DL 210 NET 2.0 is a large-area, dual-channel induction loop amplifier designed to extend hearing support to people using T-coil devices. Its coverage capacity suits auditoriums, gymnasiums, and other expansive spaces requiring a perimeter loop system. With both outputs driven, specified coverage is 31,400 square feet for a 1:1 aspect-ratio perimeter loop or 51,660 square feet for a 3:1 aspect-ratio perimeter loop. These figures provide system designers with clear starting points for planning appropriately shaped venues.

Why Choose This Model

Each loop output is rated for 12 Arms and 17 Apk, with a continuous drive voltage of 33.3 Vrms and 47.1 Vpk. The two independent outputs support large-area installations while providing the current required for loop resistance from 0.5 to 3.0 ohms DC. Network access through the RJ-45 Ethernet connection enables function control and calibration from the DigiLoop PC App. The app requires Windows 7 or higher, while firmware updates are performed through the standard-B USB connection.

The amplifier also includes input mixing, parametric equalization, compression, metal-loss compensation, high-pass and low-pass filters, automatic gain control, adjustable audio delay, and output-level control. Settings are accessible locally from the backlit front LCD using the control button and dial.

Installation and Integration

The 2 RU rackmount chassis measures 19 inches wide by 3.5 inches high by 12 inches deep, with a 17-inch-wide chassis body. Its internal universal power supply accepts 100–240 VAC at 50/60 Hz and uses an IEC 320-C14 connection. Variable-speed, temperature-controlled fan cooling supports operation from 0–35 degrees Celsius and 0–90% relative humidity.

Two configurable mic/line inputs accept balanced or unbalanced microphone signals and line levels of -10 dBV, +4 dBu, or +8 dBu. The microphone inputs have 1.5-kilohm impedance, the line inputs have 10-kilohm impedance, and 48 V phantom power is available. A separate high-level input accepts 25 V, 70 V, or 100 V signals from distributed audio or paging systems.

Integration connections include a balanced or unbalanced +4 dBu line output, a front-panel 1/4-inch stereo headphone jack, RS-232, Ethernet, USB, and a loop-fault relay. The monitored input or output can be selected for the headphone connection through the menu. Dante input is not included on this model; it is available on the DL210 NET D 2.0 model only.

Performance Highlights

The loop frequency response is 45 Hz to 9.0 kHz within ±2 dB, referenced at 1 kHz. Rated loop total harmonic distortion is less than 1% at rated output current with a 1 kHz sine wave. The specified rated load is 0.5 ohm DC with 135 microhenries of inductance. Audio output delay can be adjusted from 0 to 165 milliseconds for synchronization with other venue audio systems.

An integrated speaker output is available through the Loop Output A terminal block and can be enabled through the menu. This Class D output is rated at 225 watts into 4 ohms or 125 watts into 8 ohms, with a 20 Hz–20 kHz frequency response and 0.07% THD. The line output mirrors the audio delivered through the loop output, supporting monitoring and downstream routing.

What Makes It Different

Built-in calibration functions reduce the need for separate signal sources during commissioning. The internal test-tone generator supplies pink noise, while loop-current adjustment and matching tools assist with setup. Configurations can be saved and loaded, and the amplifier provides loop testing plus priority-input selection with an adjustable threshold.

Operational protection includes open-loop, short-circuit, and thermal protection. The integrated loop-fault relay provides normally closed, common, and normally open contacts through the DB-9 connector, with contacts rated for 2.0 A at 30 VDC. The product carries CE, UL, ULC, FCC, Industry Canada, RoHS, WEEE, CB scheme, and RCM approvals. It is designed to meet IEC 60118-4 when correctly designed, installed, and commissioned, with test specifications provided to IEC 62489-1.

Final Assessment

The DL 210 NET 2.0 combines two 12 Arms loop outputs, large specified coverage, flexible audio inputs, Ethernet-based control, and internal commissioning tools in a 2 RU rackmount enclosure. It is particularly suited to installations that need centralized configuration, distributed-audio integration, adjustable signal processing, and local or remote calibration. A two-year warranty is included.