Juggling Boxes

It is easy to juggle a single small, lightweight box (too easy to actually qualify as juggling) but as you add a second or third box it becomes apparent who has learned to juggle and who has simply learned to toss stuff in the air without any concept of how to catch it. This same dilemma is evident in many of the DSP-based processors available. If you only need one, then connection and configuration is easy. Add a second one and, in many cases, this becomes far more difficult. Add the third and now configuration and interconnection (bussing) is only practical on a few devices. Of course, there are a (very) few manufacturers that provide networked systems of boxes that knit together seamlessly and are built for master jugglers.

A comprehensive processing box will provide everything between the microphone input and the output to the power amplifier. To increase the input/output quantity to suit the application, most of these boxes communicate the necessary real-time information necessary to function as a single, larger processing device. Unfortunately, many of these devices provide spectacular examples of how fixated the manufacturer is on the unity of the single device at the expense of integrating multiple units. Two aspects of this fixation plague those that must combine multiple units into a single system: the audio signal bus and the configuration interface.

There are two simple tests to identify processors that are readily expandable into larger I/O configurations. First, do all the audio and control (NOM count, limiter sidechain, etc) signal buses connect through all of the devices? Second, do all the devices appear as a single large processor on the (computer’s) configuration display? Devices which do not allow audio to be bussed between devices as easily as within a single unit will fail the first test. Devices that require each device to be configured individually will fail the second test. Surprisingly, very few of the currently available audio processing products will pass these two tests.

We can look at the history of DSP-based processing and see the two divergent paths that developed over the past two decades. On "Path A" was the comprehensive processing box, intended to replace the sound system drive rack, which began with units, such as TOA’s SAORI back in the ‘80s. At the same time, on "Path B" the large-scale mic-to-amp processing system based on modular sub-components was being developed by other companies, such as IED’s UDAPS. Both of these companies are still producing devices that reflect a refinement of their respective approaches. In the past decade, these two concepts produced a proliferation of products. While some products were developed to leap from "Path A" to "Path B", they appear to be conceived by the unsuccessful juggler that is focused on the box in hand and drops the one in the air. Don't be confused by the physical appearance of the box, as there are products that expand effortlessly and those that do not. Both types can be found in a single box format, and some manufacturers produce both types.

Any manufacturer that produces devices that can be connected in multiples to create larger I/O configurations and does not provide a single display screen with all of the units shown together, isn't finished developing their product for this type of application. Instead, they are depending on the perseverance of systems integrators to complete the task. Some even have the audacity to provide paper worksheets to assist in sorting out the interconnection and configuration of multiple units. Along with this clumsiness, is the need to write down the settings that must be copied between I/O channels (gain, EQ, buss assignments, etc) because the software interface only allows copying within a single unit! While this compartmentalized view is barely acceptable in loudspeaker processors, it is unforgivable in the mic-to-amp processing system that claims to provide modular expansion.

This divergence in concepts is only apparent because of the excellent work that has gone into developing the systems that are not built-to-spill. We can be thankful that the pioneering work of IED, Peak Audio and others, which allow I/O expansion without compromise. Feedback from sound system designers and systems integrators has not only improved these products, they have informed the design of more recent products, such as Biamp’s Audia, which build on this legacy. Manufacturers need to understand that moving a product from a standalone device, to an I/O expansion platform, is more than just a few sub-busses on a rear panel connector. To enable the systems integrator to juggle all the inputs and outputs without dropping features or functions, the boxes need to fully share busses and configuration.

United Entertainment Media Inc.
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New York, NY, 10016
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