The March/April 2003 issue of Church Production Magazine (CPM) included an article by this author in which we stressed the destructive consequences of stage monitors on the quality of front-of-house (FOH) sound. Unfortunately, with today’s amplified music, monitors are not conveniences, they’re necessities. In the past, the professional audio industry came up with a number of means to deal with those issues presented by the use of monitors, and the better the solution, the greater the cost.
That was then. Recent history has seen the advent of a solution that can eliminate these issues: that being the personal monitor mixer. A personal monitor places monitor content and levels under the control of the artist, which is where it should be. When an artist has to direct a sound engineer to “add a little ‘this’, and less of ‘that’”, it provides, at best, a monitor mix that is a compromise and likely never the optimum. With the artist in control, he or she can dial the exact mix they want, which can greatly impact their performance. In addition, issues such as feedback are easily identified and eliminated. Should monitor feedback occur, it’s quite obvious which source is the culprit. Should the artists choose to use in-ear monitoring devices, all destructive issues presented by the presence of stage monitors are eliminated.
Generally all personal monitoring systems function alike. The signal sources of the desired monitor content are routed from the main sound console to the initial component of the monitor system, which is located near the console. This initial component’s role is to accept multiple inputs and superimpose them into a single output. This output is routed to a second component on stage (the personal monitor mixer) which is under control of the artist.
“Wait a second”, you say. “Taking multiple inputs to a single output is what a mixer does. I thought the artist was under control of the mix.”
OK, you asked for it, here’s a 10,000-foot view. The first component in this signal chain takes each of its inputs, digitizes them, then, via a technique called time domain multiplexing, assigns each input channel a unique period of time when its digital representation can appear at the output. Each input channel’s data is presented to the output and then the process repeats itself ad infinitum. This time multiplexed data is transmitted to multiple receivers which are made aware of which time frame each of the source signal’s data occupies. Each receiver (read mixer), under control of the artist, selects the data within a time frame, performs a mathematical calculation (i.e. multiplies or divides to affect its level) and adds the result to the resultants of the processed data from the other time slots. The summed digital data is converted to analog, amplified, and presented to the artist acoustically via a method of his or her choosing—standard wedge monitors (not the ideal), headphones, or in-ears.
Sound complex? You use a similar system every day. It’s called the telephone, though the comparison stops there. This type of product has much greater bandwidth and dynamic range.
The exact method of digitization, and transmission of data to the artist’s receiver varies between vendors, making mix and match systems impossible. Those hoping to build a digital sound system based around a particular standard should investigate Gibson Music’s MAGIC protocol or Yamaha’s MLAN, but that’s another article.
Let’s take a look at a product. “It’s about time,” you say?
Aviom was created by a group of engineers from Ensoniq Corporation. Aviom’s Chief Executive Officer, Carl Bader, a drummer, conceived of this personal monitor mixing system while dealing with level and mixing issues during a jam session with some friends in his basement. Since its inception in 2002, the firm has spearheaded some remarkable developments in the arena of personal monitor mixers. This writer found himself quite impressed with the obvious forethought Aviom’s engineers have put into their product, particularly in the methods employed to deal with connecting to an existing sound console, and the manner in which a receiver/personal monitor mixer can be tailored to multiple artists. In this article we will review the Aviom A-16 Personal Monitor Mixing System, although Aviom has recently developed some additional products that are worth a look by the interested reader.
The A-16 Personal Monitor System employs architecture as outlined above. A transmitter and one or more receivers are interconnected with Ethernet-standard Category 5 cable. The interconnect cable between any two components in the system can be up to 500 feet in length. Aviom’s system employs their proprietary A-Net protocol to transmit 24-bit audio data that has been sampled at a 48 kHz rate, which exceeds the quality of today’s CD digital audio.
The A-16T Transmitter is a rack-mount component and can accept up to 16 signal inputs via 16 TRS jacks on its rear panel. Although it accepts any line-level input, the system is designed to employ the pre-fader, direct output of a sound console as a source, but the product offers 16 additional “thru” TRS jacks that afford the placing of the device in an insert loop, if a given console’s direct outs are unavailable or the console doesn’t have direct outputs. Though the A- 16T’s inputs are single ended, they can accept, and pass via the thru jacks, a balanced signal. The A-16T Transmitter’s quite well written operators manual goes to some length to provide a solution to most any system interconnect that might be necessary to employ the transmitter. The front panel of the A-16T features signal and clipping LED indicators for each channel and two switches per pair of channels. One switch sets the acceptable maximum input level to –10 dB, 0 dB, +4 dB, or +22 dB. The second gangs an input pair as a stereo channel. If utilized, the personal mixer detects this configuration and treats the received data accordingly, relieving the artist of the concern of noting and controlling two separate signals as a stereo whole. Also on the front panel is a standard RJ-45 jack that accepts the Cat 5 cable routed to the receivers.
At the receiving end, the A-16 Personal Mixer shines with engineering forethought. The unit is packaged in impact-resistant plastic, and will sit on a flat surface or mount, with optional hardware, to a microphone stand. The rear panel presents an A-Net input via an RJ-45 and an A-Net output to connect to additional receivers in daisy chain fashion. A stereo TRS jack is provided for attaching headphones, inear monitors, or, if desired, this output can be used in conjunction with an outboard amplifier to drive monitor wedges. The controls presented on the upper panel include 16 switches to select which signal source will be affected by the unit’s controls for volume, pan, muting and grouping. Treble, bass, and master volume controls are present to adjust the overall mixed signal. Two switches allow any selected channel to be soloed or muted. An additional pair of switches enables a feature unique to the A-16 Personal Mixer: the ability to save and recall up to 16 mix presets. This feature might be attractive to those venues that rotate performers. Each performer can have a customized mix recallable at the touch of a couple of buttons. LEDs in the channel select switches easily identify which channel is selected, soloed, muted, or assigned to a preset.
We tested the A-16 System with our church’s contemporary worship ensemble. We employed one A-16T Transmitter and two A-16 Personal Mixers. One mixer was used by our music director/keyboardist, the second by our backup vocalists. Not having in-ear monitors available, the output from the mixers replaced our existing monitor sub mixes which drive floor wedges.
Our music director, the individual I expected to be the most critical, is thoroughly impressed and doesn’t want to return the evaluation unit. Our vocalists, on the other hand, had difficulties—not with the product, but with their desire not to offend their fellow vocalist’s by adjusting the mix to their particular liking. In hindsight, we realized this was an unfair test of the product and I mention it just to prevent others from making a similar mistake. That point stated, it could be said that even with the vocalists’ difficulties, a marked difference in their performance was noted while they utilized the system. Should your church consider purchasing a system, I highly recommend going the distance by obtaining a receiver and in-ear monitor for each vocalist.
We found the system extremely intuitive in setup and operation and have had no problems during our two-month evaluation. Though one could easily install and use the system without referencing the manual, I would recommend reading it, as it is as well thought out as the product itself and provides valuable solutions to the methods of connecting to an existing sound system under a number of scenarios.
If I were to note any deficits, I would recommend Aviom employ automatic feedback elimination and ear protection in future products. We noted no difficulties in these areas; it would just further enhance the product’s already impressive feature set.
All in all, this writer assigns high marks to the Aviom
A-16 Personal Monitor Mixing System. Though similar in function to other available
systems, Aviom has raised the bar by providing valuable features not seen in
some other products. This is clearly a system designed by musicians for musicians.
With a moderate price point, the product is extremely competitive with standard
monitor systems and, when one considers the benefits to both performance and
sound quality, the Aviom A-16 would be high on this writer’s list of
choices when upgrading or specifying a new sound system.
