The Radial ProAV1 is a passive multimedia direct box (DI) that connects almost any audio source to a PA or mixer while automatically summing stereo signals to a single mono output. Purpose-built for audio-video integrators, it accepts 1/4-inch, RCA, 3.5-mm, and line-level XLR inputs, isolates them through a custom Eclipse transformer, and delivers one clean, balanced XLR feed, halving the channel count a stereo source would normally demand. When a presentation, playback rig, or install needs a stereo device to land on a single quiet mixer channel, the ProAV1 makes the connection instantly and without hum.
A direct box performs three jobs that make consumer and instrument-level gear behave on a professional system. It converts high-impedance, unbalanced signals to the low-impedance, balanced signal a mixer expects, so tone stays full and noise cancels over a long cable run. It matches levels so a phone, laptop, or media player does not swamp a mic input. And it isolates grounds, breaking the loops between a computer or playback deck and the console that cause 60-cycle hum. The ProAV1 does all three passively, with no power required.
The ProAV1 is built around a custom Eclipse ET-DB2 transformer with a 12-to-1 ratio, and being passive means it needs no phantom power, battery, or adapter to work. That transformer is engineered to handle the extreme dynamics and wide frequency range of modern digital sources, staying linear from 20 Hz to 18.5 kHz with a huge 128 dB dynamic range and just 0.01 percent distortion. It absorbs signal peaks up to plus 18 dB without strain, so even a hot line output arrives clean, natural, and free of the harshness digital gear can produce.
The defining feature of the ProAV1 is its mono-sum design. A stereo source, a laptop, media player, or playback deck, arrives on the left and right inputs and is summed through a resistive mixer to one mono output. For an AV integrator this is the whole point: a stereo device that would normally eat two mixer channels now needs only one, cutting the channel count on a snake or console in half and simplifying the entire signal path. Where mono coverage is all a room needs, the ProAV1 gets a stereo device there on a single balanced line.
Connectivity is where the ProAV1 earns its place in a toolkit. Inputs are available on dual 1/4-inch, RCA, 3.5-mm stereo, and line-level XLR, so it can take a guitar or keyboard, a media player, a laptop headphone jack, or a plus-4 dB line output from a console or interface, all without hunting for adapter cables. Whatever the source device presents, the ProAV1 already has the jack for it, which is exactly what an integrator needs when the room's gear is unknown until load-in.
An input pad tames sources that run too hot for the transformer, so a loud line output stays clean rather than overloading. A ground-lift switch breaks the hum-causing loop between the source and the mixer for silent operation on electrically noisy systems. And 1/4-inch and RCA thru connections pass the signal onward, so you can feed a stage amp or a local monitor while the balanced XLR runs to front of house. Every control earns its place on a box meant to solve real integration problems.
In an AV install or event, the ProAV1 is the reliable bridge between consumer playback gear and the professional PA, quietly summing stereo sources to mono and feeding the console on one channel. But it also works as a standard direct box for passive and active instruments, a guitar, bass, or keyboard plugs into the 1/4-inch input, thrus to an on-stage amp, and sends a clean isolated feed to the desk. One compact box covers both the presentation rig and the backline.
The ProAV1 is for the AV integrator who needs to land stereo playback devices on a mono system without wasting channels; for the event and house-of-worship tech who wants a bulletproof, no-power box to connect laptops and media players to the PA; and for the musician who needs a quiet, rugged DI for instruments on stage. When a stereo source has to become one clean, hum-free mono channel, the ProAV1 is the passive direct box that does it.