Electro-Voice N/DYM Wireless

Name: Electro-Voice N/DYM
Brand: Electro-Voice

Ten frequency-agile UHF channels, a receiver with a 100 dB dynamic range, and the N/DYM capsule lineage behind the handhelds.

Overview

Electro-Voice's N/DYM Wireless is a family of UHF systems, not a single product. The series has ten frequency-agile channels, with transmitters and receivers operating in the UHF band between 800 and 814 MHz. This is not a VHF system, and it is not a modern wideband digital rig. It's a synthesized PLL UHF setup from the era when "frequency agile" still meant something you had to think about.

The receiver lineup centers on the NRU and NRU-G, both built around a synthesized phase-locked-loop tuning system. Ten selectable channels are available, and the design uses true diversity with EV's Secure-Phase scheme, which keeps the signal clean when one antenna path fades. According to the manufacturer's documentation, RF sensitivity is rated at less than 0.8 µV for 12 dB SINAD. That tells you the front end was built to pull a usable signal out of a poor RF environment. The receiver was approved under FCC Part 15.

The published frequency response is 50 Hz to 15 kHz, ±2 dB. That's not wideband by modern standards, but it's honest for a UHF wireless system of this class. Signal-to-noise is listed at greater than 94 dB, and the dynamic range is quoted at 100 dB. Distortion is under 0.5%. Outputs come both ways: a balanced three-pin XLR at -20 dBV into a 600-ohm load, and an unbalanced 1/4-inch jack adjustable from 8 mV to 0.775 V RMS into a 100-kilohm load. With both on the receiver, the N/DYM Wireless can drop into a house console or a small-format mixer without a DI box in between.

The transmitter side covers a family of bodypacks and handhelds: the NBPU and NBPU-G bodypacks, and the NHTU-N1 and NHTU-N2 handhelds. The handhelds carry N/DYM microphone heads, so this series inherits the N/DYM capsule technology that Electro-Voice developed for its wired microphones. The N/DYM name is tied to neodymium magnet structures. EV's period advertising was blunt about it: the company billed itself as the first to discover and apply neodymium technology in professional audio products, and pointed to the exclusive N/DYM high-frequency driver as proof. Whether that "first" claim holds up or not, the neodymium lineage is why the N/DYM badge appears on both microphones and this wireless line. Mix (May 1992, p.114) described the N/DYM performance hallmarks in the Series III advertising as studio condenser frequency response, low distortion, and high output.

Setup is handled by ClearScan, which the manual describes as the tool for finding operating frequencies when no more than two systems will be used at once. For larger deployments, EV publishes specific channel groupings: channels 0 through 4 will work together, or channels 5 through 9, but not an arbitrary mix across the two groups. That bites anyone who buys three systems off the used market and expects them all to cooperate. The manual is explicit that when more than two systems are in play, ClearScan should be used to pick the first channel, and subsequent systems should be assigned according to the published groupings.

The system also offers a choice between two handheld units and four bodypacks, plus a dedicated guitar system, and permanent antennas are fitted for quick setup. A separately available kit allows rack mounting. The manual notes that the receiver should be placed away from large metal objects or surfaces, and as close as possible to where the transmitter user will actually be working. That applies to any UHF wireless rig, but the 800-814 MHz band is not forgiving of bad antenna placement.

On interference, EV's documentation is direct: any electronic product containing digital circuitry - signal processors, electronic keyboards, digital lighting controllers, CD players, computers - emits RF energy that can degrade wireless performance. The remedy is distance. Put the receiver as far from those devices as practical. The manual also covers batteries, recommending fresh 9-volt alkalines from a quality manufacturer for best performance. Rechargeable 8.4-volt NiCd cells can be used, but with much shorter operational time. The transmitter's red battery light flashes once on power-up if the cell is good. If it doesn't flash, or stays lit continuously, the battery is weak or dead. If the light comes on during use, the battery is fading and should be replaced soon. Degrading sound quality mid-performance is a classic symptom of a weakening battery, and the manual flags it as such.

Warranty coverage for Electro-Voice wireless systems was one year from the original date of purchase against defects in materials and workmanship, with cables and cable connectors excluded. Factory service in North America ran through EV Audio Service c/o Telex Communications in Lincoln, Nebraska. European service went through Telex EVI Audio GmbH in Straubing, Germany. The limited warranty excluded exterior finish and appearance, and any malfunction arising from misuse, abuse, or repairs performed by anyone other than EV or its authorized representatives.

The N/DYM Wireless is a professional UHF system from the era before digital wireless and before the 700 MHz band reallocation pushed so much gear into obsolescence. The 800-814 MHz range has its own regulatory history, and anyone buying into this band today should confirm local legality before transmitting. The receiver's 100 dB dynamic range and >94 dB signal-to-noise figures still read well. Mix (June 1994, p.126) noted that the N/DYM Series III microphones had received the magazine's TEC Award for excellence in transducer design.

The N/DYM Wireless is not a plug-and-play modern system. It has ten channels, two fixed groupings, permanent antennas, and a receiver that wants to live near the performer and far from anything digital. For a small venue, a house of worship, or a club install where the RF environment is known and the channel plan can be controlled, it offers professional-grade audio performance. For someone who wants to hand four systems to four performers and walk away, the channel groupings will be the first problem.

Bodypacks, handhelds, and the rack kit were all separate pieces of the system, and a receiver without its matching transmitters is a paperweight. The 9-volt battery requirement means no proprietary charging dock to lose. Service documentation points to Telex-era support channels that have long since changed hands, so any repair today means finding a tech who knows UHF RF work rather than sending it back to the factory.