There was a time when roll-around office chairs were essential for a well-equipped MIDI studio. Scooting about on four wheels was the only way to reach

There was a time when roll-around office chairs were essential for a well-equipped MIDI studio. Scooting about on four wheels was the only way to reach equipment that needed adjusting, short of standing up and actually walking over to it. Today, thanks to MIDI, digital audio sequencers, and an odd assortment of peripheral gear, you can control an entire studio while seated in one spot. Four-wheel drive is no longer required.

But setting up a central command station for your studio can be daunting. Without a clear understanding of how to configure the software and hardware components of such a system, it's easy to get frustrated and give up before fully realizing the power that you can have literally at your fingertips. In this article I will walk you through the basics of putting together a comprehensive centralized control setup, including hardware, software, and all the dirty details necessary to get things working properly. So strap yourself in, bolt down your chair, and prepare for takeoff.

MIDI was originally conceived in the early '80s as a way for electronic musical instruments to communicate, but it has far outgrown its acronym. Today, almost every piece of studio equipment-not just musical instruments-is outfitted with MIDI, from effects processors to sound cards, multitrack recorders, and even mixing boards.

Written into the MIDI protocol are several data types that allow external control of your MIDI devices. Without them, it would be impossible to hook up a central command station to control your studio. The most important of these data types for our purposes are Control Change (CC), SysEx (including MIDI Machine Control), and Program Change messages.

The MIDI specification defines 128 CC messages (numbered 0 to 127). Almost all gear transmits and responds to at least a few of these-and some to all 128. CC messages handle a wide variety of MIDI parameters including Volume, Pan, and Modulation. (See the table "MIDI Control Change Numbers and Their Associated Data Types" for a complete list of Control Changes.) Many messages are assigned to control specific parameters; others are left open or "undefined," allowing developers to cook up their own assignments.

Although CC messages are generic and apply to all MIDI gear, SysEx messages are product specific. With SysEx, a manufacturer can conjure up a control number for any parameter on its equipment, no matter how esoteric that parameter is. For example, an effects unit's highpass filter frequency-select parameter can be given a specific SysEx value. Control of that particular parameter is then achieved by sending the correct SysEx number to the effects unit-simple. Most MIDI devices have SysEx numbers assigned to all of their parameters, but finding out what these numbers are can be difficult. If it isn't in the manual and you can't access the parameter with a physical control on the unit's face, you'll need to get the information from a user group or directly from the manufacturer. (Most modern gear, such as Clavia's Nord Lead or Electrix's Warp Factory, transmits SysEx via knobs, buttons, and sliders.)

Program Change messages are nothing new to most MIDI initiates. Send your sound module or effects unit a Program Change, and patches are magically recalled-no in-depth explanation needed here. All MIDI gear capable of storing patches responds to Program Change messages.

A control protocol that was added later in MIDI's history is MMC. (MMC actually employs SysEx messages, but because it's used only for a particular set of operations, simply treating it as its own controller type is acceptable for clarity's sake.) Designed for the remote operation of video and audio decks, MMC is perfect for controlling your MIDI-equipped multitrack (for example, E-mu's Darwin, Roland's VS-880, or an ADAT with a proper MIDI interface). With MMC, you can handle transport functions, enable tracks for recording, set locate points, and so on, so that running your multitrack from afar is a snap. Most professional-level digital audio sequencers support MMC, as do many of today's MIDI digital mixers (such as Tascam's TMD-1000 and Ramsa's WR-DA7). You'll typically find dedicated controls, including transport and location keys, directly on the mixer's face.

The cornerstone of a central command station is your digital audio sequencer. It functions as the brain of the system, allowing you to assign, route, and manipulate a wide range of MIDI control data. Nearly all major digital audio sequencers will record and play back CC and SysEx data and, of course, transmit Program Change messages. However, not every program offers comprehensive data remapping (turning one type of control into another, for example) and custom control panel options (or "templates," which I'll discuss shortly). The digital audio sequencers that I worked with when writing this article are all up to the task. This group, consisting of Mark of the Unicorn's Digital Performer, Emagic's Logic Audio, Steinberg's Cubase VST, and Cakewalk's Pro Audio 9, is by no means definitive-other worthy programs are certainly available. These are merely the sequencers that I had time to test.

Although it's possible to control some of your studio using only a digital mixer with MIDI capabilities, you can't record MIDI tracks or automate MIDI performance data without a sequencer. The limitations are obvious (okay, I suppose if live recording is your sole objective, you could get by). In addition, many digital mixers have only onboard, scene-based automation and actually require a sequencer for full dynamic automation. But team a digital mixer with a digital audio sequencer and you've got an extremely powerful combo. Digital mixers make great control surfaces when hooked up to a properly configured controller template (again, more on this later).

The backbone of your command station is the MIDI interface/patch bay. From this device, all MIDI messages coming in and out of your digital audio sequencer are piped to their assigned destinations. Not having a MIDI patch bay is like having a head without a spinal cord: you can see your body, but you can't communicate with it. These days, MIDI interface/patch bays perform a variety of additional chores, including MIDI processing and mapping, data merging, and synchronization; an example is MOTU's MTP AV. A single-port interface without a patch bay is fine for rudimentary systems (a computer and a keyboard, for instance), but for full-fledged control of larger systems, a multiport MIDI interface-which can provide up to 128 MIDI channels-is essential.

Templates are groups of virtual elements (including knobs, buttons, sliders, dials, and text boxes) strung together to make an onscreen MIDI control console (see Fig. 1). Many digital audio sequencers (such as Pro Audio 9) allow you to build these consoles completely from scratch and to assemble whatever elements are desired for your custom control template. Most programs also offer numerous preset templates for remote control of a variety of gear ranging from generic General MIDI sound modules to specific synth consoles and effects units. Many manufacturers and user groups offer downloadable preset templates in various formats on their Web sites.

How a custom template is created varies from program to program. Generally, it's a matter of adding elements to your virtual console by either choosing them from a menu or doing the click-and-drag dance with a palette bar. You then assign a specific type of MIDI control data, the desired MIDI channel, and a MIDI output port to each element. This is often accomplished by typing information into text fields or by putting the console into "learn mode." Learn mode is the generic term for a ready state in which an element can be taught what type of data it will output. With learn mode on and the element selected, simply send the MIDI data that you want assigned to it (perhaps by moving a knob or slider on a physical hardware device) and you're done. With each element in your console outputting specific control information, you're ready to take command of your targeted MIDI device (which could be an external MIDI sound module, an internal sound card, or even a software synthesizer or sampler).

A well-designed digital audio sequencer will let a virtual console element respond to one type of MIDI data and output a different type. This would, for example, allow a knob or slider on one device to generate CC data with which it can control a parameter on another device that normally responds only to SysEx. The trick in setting up this type of remapping is to be sure that each console element is configured properly, that input and output data fields are assigned correctly, and that your digital audio sequencer's patch-through parameter is enabled. With patch-through on, incoming MIDI data is automatically routed to the control-template element and then out of the MIDI interface to its associated hardware device. (You will often need to select either an instrument track or a dedicated template track to route the incoming data properly.) This is the same method that you would use to route a control keyboard to different devices. The advantage of this system is that any MIDI unit can act as a control surface, whether it's a synth module with knobs that transmit CC data, a dedicated MIDI fader box, or a digital mixer.

Finally, just to clear up any confusion, two common types of templates are available-MIDI templates and audio templates. MIDI templates control internal and external MIDI devices, using either SysEx or CC data. Audio templates typically receive SysEx data generated by external MIDI control surfaces and then route the data to the sequencer's digital audio mixer. Although MIDI templates are completely user-definable, audio templates are not. A manufacturer must create a special template or "profile" to allow a control surface, such as Mackie's HUI (Human User Interface) or CM Automation's MotorMix, to control the sequencer's audio mixer section. With luck, users will have the ability to create their own audio templates in the near future.

Five basic groups of gear can be controlled via MIDI: sound modules (which include MIDI keyboards used as sound modules), effects processors, multitracks, mixers, and audio control devices (for example, VCA automation devices-more on these soon). We'll look at all of these groups in turn. Each has a set of parameters that is usually remote-controlled (see the table "Typical Remote-Control Parameters and Their Control Types").

I'm probably stating the obvious, but it's important to mention: any equipment that can be controlled via MIDI can be automated. And, of course, the automation data (the information that's recorded into your sequencer) can be endlessly tweaked to your heart's delight. With the powerful data-manipulation tools found in most of today's sequencers, the possibilities for using MIDI to control all types of gear are endless.

Synth-O-Matic. Sending program changes to MIDI sound modules is the inalienable right of all MIDI musicians. Every digital audio sequencer that I've ever encountered can generate Program Change messages, making the remote switching of sounds a snap.

But patch changing only scratches the surface of what you can do with most modern sound modules. A huge range of parameters can be controlled remotely, including volume, envelope times, resonance amounts, and even built-in effects. Generally, these parameters are accessible through Channel Voice or SysEx messages.

With a control template properly configured for your module, sounds can be designed on the fly. So your keyboard player could be practicing a part at the same time you're tweaking that keyboard's current patch from your computer. Even after the part has been recorded, you can continue to adjust parameters while the track is playing back. Best of all, the template on your computer monitor can be as big or as small as you like-no more staring into a tiny, poorly illuminated screen.

Affecting effects. Most of today's effects processors can store patches. As you would expect, these patches can be switched using program changes. This lets you create dramatic shifts in effects over the course of your composition. For example, you could dial up a small-room reverb for your verses to create a tight, intimate sound, and then jump to a large-hall reverb on the choruses for a heavenly cathedral effect. Just be careful when you swap patches; a program change in the middle of a reverb tail can sometimes cause a nasty pop.

An effects processor's sound-sculpting parameters (such as EQ, compression, distortion, and ADSR) can usually be controlled using SysEx or CC data. If you set up the elements in your template to send the proper messages, you'll have command over a myriad of sound-mangling possibilities. My favorite trick is assigning a fader element to a resonance parameter: slide the fader up and down in time with your music while recording the performance to create automated resonant sweeps that match your beats. If your effects unit lacks a resonance parameter, try using a distortion setting or a phaser/flanger value. Automating effects changes is a blast.

Multitrack racket. Often, audio gear makes an awful noise, from whining motors in tape-based machines to whirring fans in hard drive systems. Getting this equipment out of hearing range greatly improves the listening environment of your control room. With MMC you can shove your multitrack into the far corner of the room without giving up one iota of control; you should need to touch the machine only for tape loading or hard drive backup.

An MMC command panel can be either virtual (on your computer screen) or real world (as on a MIDI digital mixer). A typical MMC panel in a digital audio sequencer is shown in Fig. 2. Accessing your multitrack functions onscreen is okay, assuming that you don't mind punching in with your QWERTY keyboard or rewinding with your mouse. I much prefer the feel of physical keys or buttons-such as those found on a digital mixer-or a device like the JLCooper Cue Point. These controls are much more ergonomic and reassuring, giving you the feeling that the multitrack is right under your fingertips.

The main thing to watch out for when configuring an MMC system is closed-loop versus open-loop operation. Choosing closed- or open-loop designates the type of communication to be used between the controller and the multitrack (specifically, whether two-way communication is required). Both the digital audio sequencer and the multitrack should be assigned the same setting; otherwise, you're asking for problems. Check the manuals to see if your multitrack and sequencer are compatible.

MMC has two small drawbacks. First, it's using MIDI; there's some delay between the time you hit an MMC button and get a response from the multitrack. This isn't usually a problem, but when you need a tight punch, it can be unacceptable. Every system has a different amount of machine lag, and there's no telling how bad yours might be. For razor-sharp punches, however, try automating the record-in and record-out points. This usually does the job, because the digital audio sequencer compensates for time lag to make the perfect punch. MMC's second drawback is that its panels don't mirror your deck's meters; this requires that you keep your multitracks in view for monitoring.

Digital mixers. Most digital mixers can do more than just control your audio-they can also control your MIDI tracks. A good digital mixer will have a mode dedicated exclusively to handling MIDI. In that mode, the console's input strips become MIDI control strips, with each one corresponding to one or more MIDI tracks in your sequencer. By flipping between the board's two modes, you're able to command both audio and MIDI from a single control surface.

At the most basic level, you'll have control over track volume, mute, and pan. This is usually done by sending Control Change data from the mixer's physical controls. You may find that the mixer allows you to send other forms of data too, such as SysEx messages. As usual, any or all of this information can be mapped to a template of your creation.

Keep in mind, however, that the same control on each channel strip typically transmits identical forms of data-for example, every fader transmits CC 7. This is why each strip must have its own MIDI channel; otherwise, one-to-one discrete control of individual MIDI tracks would be impossible. (On certain consoles, the MIDI channels and control types can be flexibly assigned, but this is the exception, not the rule-normally, consoles are preset.)

Another use for a mixer is to control the individual sounds of a multitimbral module, especially one with just stereo outputs (as is the case with many GM modules). Using the mixer's audio mode, set the module's stereo output to a comfortable level (0 dB, for example) and lock it in. Then, when you want to change a specific patch's level on the module, simply switch to the MIDI mode and grab the appropriate fader. If you have all of your MIDI assignments and templates configured correctly, controlling levels in this fashion should be a piece of cake.

Audio control devices. A number of MIDI peripheral devices for controlling audio are now on the market. They range from voltage-controlled amplifiers (VCAs) used for handling signal levels to MIDI-automated audio patch bays and remote-controlled preamps. If you're missing that final link in your quest for ultimate studio control, this diverse group of gear may be the key.

VCA modules (such as the Niche Audio Control Module) are great for controlling volume levels on a multitrack, especially if you don't have an automated mixer. All VCA units come with an audio input and output. Insert the unit between the output of your multitrack and the input of your mixer. Make the necessary MIDI connections and set up a template for control. Most VCAs use a single MIDI channel and respond to consecutive CC numbers (one number per audio channel). Using your template's faders, you can now automate the levels of your multitrack-pretty cool.

MIDI-controlled audio patch bays are rare but handy. A 16-by-16-point unit called the AudioMatrix Patcher was once made by 360 Systems. Currently in production is CM Automation's 16-by-16 PM-216; the company also makes a 32-by-32 model, the PM-64. You can control the PM-216's routings by software (Windows only) for comprehensive remote patching. Patches can be saved into one of 64 program slots. This means that-you guessed it-the programs can be recalled using Program Change messages. It's a perfect patch bay if you have, say, only a 12-channel mixer and 16 sound sources. Using automated patch changes, you could actually switch the inputs to the mixer while your song is playing, without missing a beat. (Of course, in this example you're limited to just 12 inputs, but you get the idea.)

Who knows what the manufacturers will cook up next to satiate our audio-control needs? Summit Audio's new Extension 78 plug-in for Digidesign's Pro Tools 5.0 is probably a good clue. This plug-in gives you direct MIDI control over Summit Audio's Element 78 line of Class A analog signal processors and preamps. No template programming here-just make the MIDI connections, call up the plug-in, and sit back: you've now got complete control of external equipment directly from your digital audio sequencer. (For those who haven't heard, Pro Tools 5.0 now has a MIDI sequencer, so it's officially a digital audio sequencer.) Imagine the possibilities-I'm sure we'll be seeing many more hardware/plug-in systems like this for every conceivable application.

Many fine real-world control surfaces with physical dials, keys, and sliders to twist and push are currently available. They range from a studio keyboard to a module with SysEx buttons to a box with knobs that generate CC data. Anything that transmits MIDI messages can be mapped in a control template.

A control surface that's rarely thought of as such is right under our noses-the common MIDI keyboard. All keyboards have a modulation wheel that's perfect for controlling volume. Just create a template, map CC 1 (the mod wheel's controller number) to output as CC 7, pick a device to control, and voila-a nifty level controller. This same concept can be applied to any of the keyboard's buttons (assuming that they transmit their values via MIDI) and even to the ivories (see Fig. 3). If you don't have a keyboard but you own some other type of MIDI instrument-drum pads, guitar controller, or wind instrument, for instance-there's no reason that you can't use it in place of a MIDI keyboard.

Many types of dedicated controller boxes have recently shown up on the scene (see the table "MIDI Control Surfaces"). The simplest of these boxes are diminutive in size, fitting neatly on a desktop or the face of a keyboard, and are reasonably priced (less than $500). They're outfitted with some combination of faders, buttons, and knobs that transmit either CC or SysEx messages. The MIDI controller data that they output is usually fixed, but some units contain patches or different modes with remapped sets of controller data. Usually, the patch parameters will match a specific piece of hardware or software (for example, the PhatBoy has a mode to control Roland's JV-1010/2080).

The most complex breed of MIDI controllers is the mixer control surface, such as the MotorMix or HUI (see Fig. 4). These units have their own proprietary sets of SysEx messages that must be mapped by the digital audio sequencer's manufacturer to work with the program's audio tracks. Although it is theoretically possible to map mixer control surfaces' SysEx messages to a MIDI control template, you certainly have better things to do with your time, such as making music. These devices are fabulous for controlling the audio in your digital audio sequencer, whether you're writing complex automation moves or tweaking plug-ins-but unless preset MIDI control templates are included, forget about using them as MIDI track controllers.

No matter how your studio is laid out, stacked up, or spread around, the bottom line is that it can all be controlled from one central location. This is a definite ergonomic advantage, regardless of your situation. But even if having complete control over every nook and cranny isn't your cup of tea (because, honestly, setting up all of this stuff can take quite some time), having remote control over at least a few of your favorite parameters is wonderfully convenient. Being able to switch patches on your sound module, control your multitrack, design a new effect, or automate an old one-all without leaving your computer-can, in the long run, be a great time-saver.

In the end, what's important is not that we have every item in our studio hooked up to and controlled by our central command station, but that we have the ability to make it so. I hope that this article has painted a picture of the possibilities. A little tweaking can go a long way toward making your studio much more efficient and powerful.

Erik Hawkins is a musician and producer working in Los Angeles County and the San Francisco Bay Area. Visit him at www .erikhawkins.com for more equipment chitchat and tips on what's hot for the personal studio.

In addition to CC and SysEx messages, a well-implemented MIDI sequencer will provide a host of other MIDI commands that can simplify and enhance your studio setup. Here are a few that make my life easier.

A MIDI keyboard can be used to send Aftertouch for modulating effects. For example, I've found that laying into the keys to speed up or slow down a Leslie effect offers a more tactile approach than using an onscreen slider, a modulation wheel, or even a footpedal.

A sequencer template with Local Control Off messages can eliminate the routine of burrowing through submenus on your keyboard just to set it up as an effective MIDI controller.

In the old days, layering synth sounds was a matter of selecting complementary sounds on each, setting the desired synths to the same MIDI channel, and perhaps disabling Program Changes so that the proper patches would be retained. Most modern sequencers can assign a single MIDI track's output to a group of devices, each receiving on its own MIDI channel. These virtual synth stacks can be edited, saved, and recalled together with the proper patch for each synth.

Tired of kneeling by your rack just to change your sound module's default mode? Fed up with hearing your old Casio synth play your drum patterns? Sending Channel Mode messages (for example, Omni Off, Mono) from your sequencer instructs your errant gear to mind its own business.

Is your master MIDI controller a tad weak in the MIDI implementation department? Your sequencer (or even your MIDI patch bay on its own) probably has a slew of remapping capabilities that can send commands that your original controller wasn't designed to send. For example, my MIDI guitar controller doesn't send Aftertouch, but with my sequencer I can easily remap the guitar's expression pedal to send it.