Developments in Computer Control: EASE OF USE IS KEY

Measurement and analysis are essential in the design and assembly of large-scale sound systems, and most touring sound pros have developed techniques
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Measurement and analysis are essential in the design and assembly of large-scale sound systems, and most touring sound pros have developed techniques for equalizing a system in various environments. However, many engineers have been slow to adopt the new tools and technologies. Some prefer to rely on standard clusters and arrays that have been "pre-balanced" by the manufacturer or system designer, and many find it easier and quicker to EQ the system by ear. But there are a number of engineers who would like to use analysis systems but are put off by the complexity that results when each system and subsystem requires its own crossover, EQ and limiters.

Rackmount devices typically allow limited physical room for controls and displays, and the sheer number of features available on today's DSP-based systems often results in a front panel interface that resembles a maze. Just finding the control you want to adjust can be a challenge, and users are often frustrated by the labyrinthine process of navigating through pages to gain access to a required parameter. Multiply this frustration by the number of subsystems in the typical large touring system and most engineers will turn to something more rewarding and manageable, like restriping the board.

Clearly, this application is crying out for computer control. An integrated laptop computer-based system that allows for quick and accurate optimization of a sound system can help the operator focus on the optimization process, rather than on manipulating the hardware and measurement tools. Such a system would automate and simplify the setup and control adjustment process and could also display the effects of changes in system control parameters. Under show conditions, the ability to control a device from a computer screen may be much easier than reaching over to a rack and scrolling through menus. And as EQ and delay parameter controls would be integrated into the measurement platform, the operator would be able to sit up and face the music, instead of bending over to reach a rack.

Though several computer-based measurement and analysis systems are available, Smaart Pro from SIA Software Company Inc., is emerging as the de facto standard, at least for computer control. In addition to its real-time measurement program, Smaart Pro offers direct computer control of a growing number of popular equalizers and system controllers. The Smaart Pro graphical user interface (GUI) can display a wide range of parameters on a single screen and is actually easier to use than many of the hardware interfaces it models or replaces. Further, the same GUI that displays the speaker system response may be used to engage the filters needed to smooth out response bumps-simply click and drag on the offending curve. In Smaart Pro, most of a control unit's parameters can be displayed onscreen and the results of changing a parameter can be instantly measured and displayed on the same screen.

Smaart Pro offers a Microsoft Windows "look and feel" interface that is consistent from one manufacturer's device to the next-whether it's a graphic EQ, a parametric or a full-blown system controller. Filters may be set by clicking and dragging, nudging or typing in numbers. Analog purists who don't want digital processing are not excluded-Smaart Pro will control the digitally controlled analog filters in the BSS VariCurve parametric EQ and the Klark Teknik graphic EQ. (It should be noted that many live sound applications require delay synchronization for full optimization, so a digital-free signal chain may not always be possible.)

SMAART PARTNERSThough only the BSS VariCurve was supported in Smaart Pro Version 2, there is now a Smaart Pro-supported device to suit nearly every situation or preference. One of the major changes in Smaart Pro Version 3 is that most of the code for controlling external devices has moved out of the main program into "plug-in" drivers. Version 3 also runs faster, useful for owners of older, slower Pentium computers. Adding support for new devices is just a matter of dropping the driver files into the Smaart Pro Devices folder as they become available. Smaart Pro Version 3.5 has been shipping since last November and supports five equalizers and four controllers.

Drivers for many more devices are under development. SIA is currently testing drivers for XTA's DP 200, 202, 224 and 226 system controllers, EAW's MX8600, the BSS FDS-366 Omnidrive Compact Plus, Sabine's GraphiQ, Klark Teknik's DN3600 and the AudioBox from Richmond Sound Design. Support for Smaart Devices for the Peavey's MediaMatrix is imminent, a development that will allow direct control of EQ, gain and delay in MediaMatrix software devices that conform to a specific naming convention.

Several of the new drivers will be ready for release by the time you read this, and Smaart Pro support for a number of other devices is in the works. New device drivers for Smaart Pro will be posted on SIA's Web site (www.siasoft.com) as they become available. (Though SIA was purchased by EAW in early 1999, JBL's Pro Audio division will continue to handle distribution of Smaart Pro. Visit www.jblpro.com for dealer information.)

HARDWARE LOGISTICSMost Smaart Pro-controlled devices connect to the computer via MIDI, and some also have an RS-232 serial connection, in which case either port can be used. Virtually every Windows computer has an RS-232 serial port, so a $15 cable will connect Smaart Pro to an EQ or controller that has an RS-232 port. Media Matrix, the BSS 355/366 and the JBL 260 require a Null modem cable, sometimes referred to as a "Laplink" cable. This cable is also used for upgrading the firmware on earlier revisions of the 355 and 260. The Shure, Ashly and Rane units use a regular serial cable.

The older devices (the VariCurve, TC 1128, JBL 280 and BSS 388/380) are MIDI-only, so once again MIDI is the lowest common denominator for computer control. With MIDI you should be able to link any 16 products as long as they have unique channel numbers, but some have proprietary system commands that could cause problems. Many products are available as slave units with no front-panel controls and are designed specifically to be controlled from a master unit via MIDI. For controlling MIDI-only devices, the computer obviously needs to be equipped with a MIDI port.

Investment in a MIDI adapter will provide for connection to the greatest number of Smaart Pro-controlled devices. And, due to its widespread use in music and audio products, MIDI also provides the connection for a number of other applications. Most laptops will require an outboard MIDI box that connects to a serial, parallel or USB port. Inexpensive, simple models (around $100) include MOTU's PC-MIDI Flyer, Midiman's Portman PC/S or PC/P (S for serial port, P for printer port) and Opcode's MIDI Translator PC. For the relatively few notebook computers that have a joystick port, adding a MIDI port is as simple as adding an adapter cable.

Users who demand Windows NT are better off looking for a computer with a joystick port-either on the computer itself or on a mini docking station, as third-party MIDI I/O boxes with NT drivers are not commonly available. USB is fully implemented in only Windows 98 and 2000 but will probably become the connection method of choice for PC peripherals in the future.

SIA has plans to support true network control of devices in future releases and is promoting Ethernet control to various hardware manufacturers. SIA is also developing software improvements that will simplify operation and further reduce the learning curve. SIA is also managing an ongoing program of educational seminars and workshops at EAW headquarters in Whitinsville, Mass., and around the world.

SOFTWARE CONSIDERATIONSOf course, many of these different Smaart-supported devices also include proprietary control software. Windows will only let one program have one I/O port at a time, so jumping between Smaart Pro and the manufacturer's control software is easier in some cases than others. For example, the Shure control software for the DFR11EQ has a Disconnect button that releases the serial port; SIA therefore put a Disconnect button in the Smaart Pro interface for the DRF11EQ. This allows the two programs to coexist fairly peacefully. You just have to disconnect from one before connecting to the other. In other cases you might have to exit from external device control in Smaart Pro, or exit the other program entirely.

Communication between Smaart Pro and external devices is bidirectional, so you always know what you're getting. Every few seconds the Real Time module reads the state of all the supported controls on the remote device(s) so that any changes made from the device's front panel or from another control program show up almost instantly on Smaart Pro's screen. In other words, Smaart Pro doesn't just send a command and assume it happened or assume that the controls are where they were left. This means you can still reach over and make adjustments from the front panel the old-fashioned way. Changes you make by hand will be reflected in the onscreen display.

MULTIPLE UNITSControlling several units of the same type should not be a problem since every manufacturer has some kind of linking capability built in into its remotely controllable products. MIDI-controllable devices can be "daisy- chained"-the MIDI Out on the first unit feeds into the MIDI In on the next, and so on. MIDI Out on the last device then comes back to the computer's MIDI In to complete the circuit and allow bidirectional communication.

When using serial control, you connect to the first device with a serial connection then chain successive units to the first. Connections between devices are made using serial cables, XLR or MIDI cables, or some proprietary connection scheme. In some cases, you have more than one option. Many, if not most, remotely controllable devices are speaking MIDI language irrespective of the physical connection, so 16 devices (or audio channels) is a common limit. The Rane RPE 228 is a notable exception, allowing as many as 250 devices (for a total of 500 audio channels) to be controlled through a single serial port. In some cases you can also set two (or more units) to the same MIDI channel and control them as a single, linked multichannel device.

Controlling several devices of different types can be a little more of a challenge. The reason is that the ability of the devices themselves, whether serial or MIDI controlled, to ignore or pass on commands not intended for them is limited in some cases. The practical result is that each device, or chain of like devices, usually needs to be connected to its own port. Serial devices can get around this to some extent with a simple serial switch box. There's no elegant way of dealing with multiport MIDI boxes in the current release of Smaart Pro, though this issue may be solved in the next software revision.

PRACTICAL CONSIDERATIONSIn general, a road warrior's laptop is frequently used for communication with the world at large, meaning that its fax-modem device needs a regular Com port assignment. This leaves one other Com port available for connection to audio devices. The Com port assignments (and their interrupts, or IRQs) should be checked in the setup utility during a computer's start up. Each audio device also needs to have its communication parameters checked on its utilities menu, even if just to check the MIDI channel.

Unless you're really comfortable with the track-pads or pointing devices common in laptop computers, you may want to carry a mouse. A trackball is particularly nifty for moving around software control panels. Much of the configuration for setting up controllers can be done offline, which can save time and eliminates the possibility of inadvertently changing critical routing or crossover settings onsite. I recommend that you test-drive the system before trying it on a show. Of course, any settings you archive to floppy may be transferred to another similar device.

The usability of many current DSP-based audio devices is hampered by their necessarily complicated user interfaces. Smaart Pro control bypasses any shortcomings of an audio device's front-panel control layout. Instead, it exploits the full value of the unit's back-panel connections, features implemented in software and sound quality. By providing a platform for both sound system analysis and computer control of a wide range of outboard EQ and processor models, even a modest laptop computer can immensely streamline the analysis and correction process, offering a powerful addition to the tools in your audio arsenal.