Audio Review: Symetrix Automix Matrix 780

The latest automixer tool in the Integrator Series proves to be a powerful combination. 1/01/2009 7:00 AM Eastern

Audio Review: Symetrix Automix Matrix 780

Jan 1, 2009 12:00 PM, By John McJunkin

The latest automixer tool in the Integrator Series proves to be a powerful combination.

Symetrix Automix Matrix

A while back, I took a look at the inaugural product in Symetrix' Integrator Series, the Zone Mix 760. (Read my review of the Zone Mix 760 here.) Symetrix has now introduced the Automix Matrix 780, which is the third and latest tool in its Integrator Series (the second was the Deuce 722). As evident in its name, the original Zone Mix 760 was marketed as a pure and simple zone mixer, intended for applications such as restaurants, sports bars, and fitness clubs. The Automix Matrix 780, on the other hand, is touted as a more sophisticated automixing matrix unit, intended for automixing, submixing, routing, and processing for applications such as courtrooms, legislative and government chambers, corporate boardrooms and training facilities, and houses of worship. The 760 is intended for multizone BGM/paging applications, whereas the 780 is a more straightforward mixer.

Fundamentally, the Automix Matrix 780 is a 12-channel automixer with eight submixes married to eight outputs. Eight of the 780's 12 inputs can handle both mic- and line-level signals, and the other four are line inputs, strictly speaking. All feature polarity inversion, a noise generator, digital trim, and British EQ. The mic/line inputs also feature a compressor and an eight-band feedback fighter. The four line inputs also have an automatic gain-control circuit. All 12 input signals flow through the 780's automixer, and then to virtual channel faders (represented in the 780's computer graphical user interface), and then on to the 12x8 matrix. Each matrix node offers an on/off switch and a level control, as do each of the matrix' eight outputs. Each output features loudspeaker management DSP — including a delay, high-pass filter, low-pass filter, eight-band parametric EQ, and a limiter. An emergency mute, which can be controlled by Symetrix' analog control inputs, mutes all outputs. Final output metering is featured on each channel, as is a -10dB/+4dB pad. The 780 — just like the 760 and 722 before it — can be controlled remotely by Symetrix' Adaptive Remote Control (ARC) wall controllers — primarily the ARC-2, but other units are available, including the ARC-2i, the ARC-K1, the ARC-SW4, and other similar versions. Many parameters of the 780 can be accessed from these controllers.

The 780 sports exactly the kind of front panel you would expect from a device that's intended to be controlled by computer via Ethernet. There's an easy-to-read 2"×16" bright-white-on-blue-background LCD display just to the left of the center of the panel. To its right, you'll find three navigation buttons: menu, up, and down. To the right of that are tricolor audio-level LEDs — 12 for inputs and eight for outputs. Finally, at far right, there are three system-status LEDs: power, network, and ARC. Similarly, the simple back panel features only I/O. From left to right, you'll find an IEC AC power input; two 3-pin Phoenix connectors for external control inputs; a six-terminal Phoenix connector that represents four open collector outputs; an RJ-45 jack and a 3-pin Euroblock, together representing the system's ARC I/O; the RJ-45 Ethernet jack that connects the unit to your computer or LAN; and a DB9 connector that represents the system's RS-232 connection for third-party accessory controllers. Beyond these control-oriented connectors, you'll find the 780's outputs — specifically, eight 3-pin Phoenix connectors — followed by inputs: four 3-pin Phoenix connectors that represent line inputs and eight 3-pin Phoenix connectors that represent mic/line inputs. The initial Automix Matrix 780 units were shipped with 3-pin balanced mono plugs that were a touch too wide, making multiple connections virtually impossible. Symetrix solved the problem by shipping six 12-pin Phoenix connectors to all purchasers of the system. I do appreciate the notion of just fixing the problem rather than instructing customers to visit their local electronics supply shop. The issue has been permanently settled now: Symetrix is now shipping the smaller 3-pin Phoenix connectors that fit perfectly side-by-side.

Audio Review: Symetrix Automix Matrix 780

Jan 1, 2009 12:00 PM, By John McJunkin

The latest automixer tool in the Integrator Series proves to be a powerful combination.

I unboxed the unit, plugged it in, and followed the quick-start guide's instructions for connecting it to my LAN. When I originally reviewed the Zone Mix 760, the software was not compatible with Windows Vista, but now all Symetrix Integrator Series and SymNet software has been updated to function in Vista. I had been made aware of the fact that version 1.0.1 of the software had superseded the 1.0.0 disc that was shipped with the unit, so I downloaded the installer and installed version 1.0.1. Having been impressed with Symetrix' original software for the 760, I had high expectations for the latest revision, and I was not disappointed. Symetrix clearly spent some time developing this software to facilitate comprehensive yet simple control of a sophisticated system, and the company really nailed it. The graphical user interface is a DAW-esque mixer topology, with tabs at the top to toggle between the Gating Automix (or Gain Sharing Automix) screen — which appears as a mixer with faders — and the Matrix/Submix screen, which displays the nodes of the matrix, allowing you to turn on any channel in any submix. By clicking on the DSP button for any channel, you get a subscreen with tabs for input, equalization, compressor, and feedback parameters. For the eight mic/line channels, there are on/off buttons for EQ, compressor, and feedback suppression. The four line-level channels feature on/off buttons for EQ and AGC. Above all the GUI's virtual channel strips are seven-segment LED meters for both inputs and outputs that can display both pre- and post-automix levels.

All 12 channels feature auto, default, and mute buttons. The auto and default buttons determine whether a channel is automixed. The default button for a single channel may be depressed, establishing it as the default microphone if no one else is speaking in a boardroom application. Priority numbers at the bottom of each channel's fader, adjustable from 1 to 10, determine the priority of that channel in the system's automixing algorithm. Both gating-type and gain-sharing-type automixing topologies are available, contingent upon the application. The hold parameter determines how long a mic remains open after the speaker finishes, the off-gain parameter sets the off level globally (similar to the range setting in a pure gate), and the sensitivity parameter essentially sets the threshold level above the adaptive noise level at which a mic will open. The system can indeed incorporate microphone input to measure room ambiance and noise and adapt to it over time, a powerful feature that I really like. The number-of-open-microphones (NOM) attenuation parameter determines the attenuation amount applied when more mics come online. The NOM-count parameter determines the maximum number of open mics at any given moment.

Having discovered the Symetrix Zone Mixer 760 to be a powerful tool at a reasonable price, I had high expectations for the Automix Matrix 780 — and I am impressed. Symetrix continues to integrate excellent DSP with powerful matrix functions here, and with the capacity to control the system via Ethernet, this is a really powerful combination. If you're in the market for a signal distribution and DSP platform and you could use the help of an automixer, you really need to look at this box.

John McJunkin is the principal of Avalon Podcasting in Chandler, Ariz. He has consulted in the development of studios and installations, and he provides high-quality podcast production services.

Audio Review: Symetrix Automix Matrix 780

Jan 1, 2009 12:00 PM, By John McJunkin

The latest automixer tool in the Integrator Series proves to be a powerful combination.


  • Company: Symetrix
  • Product: Automix Matrix 780
  • Pros: Powerful routing matrix with extensive DSP and automixing.
  • Cons: None to speak of.
  • Applications: Courtrooms, government chambers, boardrooms, training facilities, and houses of worship.
  • Price: $2,399



  • Impedance: >4kΩ balanced, >2kΩ unbalanced
  • CMRR: >55dB (1kHz, typical)
  • Mic/line gain: +20dB, +40dB, or +50dB via internal jumpers
  • Mic EIN: >-127dB, 22Hz-22kHz (100V source impedance)
  • Mic phantom power: 48VDC


  • Type: Electronically balanced
  • Impedance: 200V balanced, 100V unbalanced
  • Maximum output level: +24dBu


  • Sample rate: 48kHz
  • Dynamic range: >110dB (A-weighted, input to output)
  • THD+N: -85dB typical at +22dBu (1kHz, 0dB gain)
  • Frequency response: 20Hz-20kHz, ±0.5dB
  • Interchannel crosstalk: >-90dB typical (1kHz)

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