Radikal SAC-2K Software Assigned Controller Review

Radikal's SAC-2K occupies a market niche somewhere between generic MIDI fader devices and high-end proprietary control surfaces. When used with a compliant

Radikal's SAC-2K occupies a market niche somewhere between generic MIDI fader devices and high-end proprietary control surfaces. When used with a compliant host program, the SAC-2K provides transport controls, touch-sensitive moving faders, and an array of soft buttons and knobs that control anything from EQ settings to edit functions (see Fig. 1).

Despite its USB ports, the SAC-2K works only with a MIDI connection (see Fig. 2). Radikal has been working with Apple and Microsoft to straighten out unresolved issues related to USB's handling of timing data on Macs and PCs; a suitable USB driver is expected soon. Once those issues are settled, you'll be able to connect SAC-8X eight-fader expansion units to the SAC-2K's built-in USB hub. Radikal expects to release the expansion unit concurrently with USB support.

Installation of the SAC-2K is a complete no-brainer: On a Windows machine, you plug it in and set the software to find it according to the instructions in Radikal's manual. On a Macintosh, you need to configure the Open Music System (OMS) to recognize the SAC-2K. Even if you've never used OMS, you probably won't need the manual; if you do, you'll find the instructions clear and easy to follow.

I gave the SAC-2K a workout with everything from a desktop PC running Steinberg Cubase VST to a full-blown Mac-based Pro Tools/24 Mixplus system. The SAC-2K's integration with Mark of the Unicorn (MOTU) Digital Performer is particularly nifty.


A tour of the SAC-2K must begin with a nod of appreciation to the board's design team for recognizing that aesthetic form and ergonomic function can coexist beautifully. I'm not often moved to comment on gear's appearance, but the SAC-2K is one sharp-looking control surface. Its contours and color scheme are stylish yet understated, and its layout is spacious while its footprint is reasonably compact.

About half of the SAC-2K's surface is devoted to eight touch-sensitive, motorized 100 mm channel faders and an identical ninth fader for master output level. Each channel fader is accompanied by a Select button, a Mute/Solo button, and a rotary-encoder knob for controlling pan and a zillion other parameters. All the buttons light up when pressed. The fader section is split down the middle by a double column of ten buttons designed for duties such as switching banks and selecting knob functions.

The faders on the SAC-2K feel smooth and precise, and the motors make updating automation on the fly easy. Once you start mixing with a nice control surface such as the SAC-2K, you realize that mixing with a mouse is like using step-entry to enter notes; you can get the job done, but it's not the same as playing a responsive keyboard controller.

On the first unit I had for review, the moving faders fought me and responded improperly to written automation. A firmware update from Radikal added the capability to adjust the faders' touch sensitivity; a low setting helped a lot. Still, the motors were often jittery and imprecise. Radikal reports that static electricity can cause such strange behavior, and though I'm told that many users never have a problem, the ultimate solution involves a factory-installed modification to the faders. Radikal solved the problem by shipping me a second unit with the modification installed. All new units ship with the modified faders, and users who experience problems with older units should contact Radikal to arrange for the free modification.


Eight channel faders are more than eight times better than a mouse but still short of the number of tracks many projects contain. Press the bank-select buttons to control additional groups of eight tracks. In Pro Tools or Digital Performer, you simply press a button to hop from tracks 1 through 8 to tracks 9 through 16 and beyond until you run out of tracks. For programs such as Cubase VST that group tracks by category, you first select the type of track (MIDI or audio) and then switch between those tracks with the bank-select buttons. Incremental bank shifting — moving the selection from tracks 1 through 8 to 2 through 9 and so forth — is also possible, letting you control any group of eight adjacent faders.

The rotary encoders are touch sensitive, meaning that they respond with finer resolution as you turn them more slowly, and a quick twist covers a greater range of values. Such natural and efficient behavior beats the pants off pressing a fine-resolution button. Any knob also functions as a button; pressing it selects certain functions or, in some cases, resets a value to its default (such as center pan or 0 dB). The relative value of the parameter controlled by the rotary encoder is displayed on 31 LED segments that encircle the knob like the spokes of a wheel (see Fig. 3).

One of the coolest features is the 6-inch-wide LED text over each group of four faders. Two rows of 40 characters each (10 characters per knob) display the knob parameter, parameter values, track names, and other data, depending on context. Such visual feedback lets you perform many functions without ever looking at your computer monitor. When you use the SAC-2K with Digital Performer, the unit even displays the level of your audio tracks using tiny meters.

The remainder of the SAC-2K's surface is devoted to a Jog wheel and additional buttons, including transport controls and buttons for dropping and locating markers. A sizable SMPTE/Locator LED readout is prominently displayed above the Jog wheel. A double row of six buttons above the SMPTE display alternately emulates a computer's numeric keypad and offers one-touch access to edit windows and other functions. At the top of the transport section is another set of four rotary encoders and a third text display like those above the channel faders. Along the right edge is a column of five buttons for controlling the SAC-2K in Channel Strip mode.

Like every aspect of the unit's construction, all of the buttons and knobs feel solid, notwithstanding the button whose lens came off the first time I touched it. (I simply pressed the lens back into place, and it has stayed put ever since.)


The controls have two function sets: Mixer mode and Channel Strip mode. Mixer mode lets you see and control a few aspects of many channels simultaneously, whereas Channel Strip mode lets you see and control many aspects of a single channel. I constantly switched between the modes, using Mixer mode to adjust levels and pan positions and Channel Strip mode to tweak delay times, compressor threshold, and so forth. (Exactly which parameters you can control depends entirely on the host software.) Toggling between the two modes is a snap, and the text displays and lighted buttons reveal the mode you're in at a glance.

In Mixer mode, each channel's rotary encoder functions as a pan, insert, or send control, depending on which button is illuminated in the center bank. When you use the SAC-2K with Pro Tools, the Swap function can assign the channel fader to send level and the rotary encoder to send pan, which makes dialing in exact send settings easy. Two buttons just below the knob control mute and solo status as well as track selection. Depending on the host software, you can press the same buttons in conjunction with other button presses to arm tracks to record. All the programs I used made good use of button combinations to maximize functionality.

Changing to Channel Strip mode lets the three text displays show the individual parameters of any plug-in assigned to a track. Selecting a track and pressing the appropriate button in the Channel Strip column puts all 12 knobs at your disposal for tweaking decay time, room size, cutoff frequency, or any other plug-in parameter. If an effect has more than 12 parameters, pressing the same Channel Strip button again pages through the additional parameters.

By moving a knob faster or slower, I was able to dial in exactly the settings I wanted with incredible ease. For parameters such as Bypass, I could simply press the appropriate knob to toggle its state. With everything clearly labeled and laid out across the control panel's top, the only time I had to look at the computer monitor was to see the graphic EQ curve or gain-reduction meters on some of the plug-ins.

Because individual programs handle features such as plug-ins, effects, and virtual instruments in many ways, the implementation of the Channel Strip buttons varies quite a bit. Cubase VST, for example, has dedicated equalization, which you can access with the SAC-2K's EQ button, for each audio channel. In Pro Tools, plug-ins handle the EQ, so pressing the EQ button there opens the selected plug-in's Edit window.

One of the SAC-2K's more imaginative features is its dedicated Instrument button. With any supported software synthesizer, you can use Channel Strip mode to edit individual instrument parameters. The list of supported virtual instruments includes Native Instruments B4 and Pro-52, Emagic EXS24 and ES1, Steinberg Model E, and TC Works Mercury 1.


Although the SAC-2K is a solid performer that delivers on the promise of an efficient and professional tactile interface, its implementation varies from program to program. The SAC-2K's completely configurability is its strength, but for some users, it might also be a slight problem. Each software manufacturer is able to customize the SAC-2K's functions to integrate tightly with its host software, resulting in a different set of commands for every program. Learning to use the controller with several programs (as I have) can become confusing. If you use only one sequencing and recording environment and learn the command set well, such confusion will be less of an issue.

The SAC-2K's flexibility begs for comprehensive documentation for each supported program. Online manuals are provided for Pro Tools and Digital Performer, but the Cubase VST documentation is limited to a three-page overview in the SAC-2K manual. The dedicated manuals are quite good, and as a result, getting up and running in those programs was easy. In addition, for those two programs, Radikal has application-specific function templates designed to be placed over the button fields, so you can see at a glance which button controls what function.

Finding my way around Cubase VST, however, was mostly trial and error. Radikal Technologies is largely at the mercy of software manufacturers who determine what features to implement and how to operate them within the powerful and flexible framework that Radikal has designed.

Why do control surfaces such as the SAC-2K support some programs so much more extensively than others? Enlightened developers have designed automation-code pathways into their software, enabling their programs to accept various commands from external devices. Some developers, including Digidesign and MOTU, have been doing that for years, whereas others are just now catching up. Consequently, the software developers decide which parameters will offer hands-on control — not the control-surface manufacturers, who program their firmware to address the automation code.

The implementation of the SAC-2K's controls for Digital Performer is exceptional, offering more features than any of the other host programs I tried. One particularly nice touch is that the text displays can show Help information as you work.

Pro Tools support is embedded in the most current firmware (version 1.37 at press time), and you can download a PDF manual from Radikal's Web site. You can also download a Logic Audio environment and support files for Digital Performer and CreamWare Scope. Radikal says that Magix Samplitude, Steinberg Nuendo and Sek'd Sequoia are supported, as well.

Not content to be simply a front end for audio sequencers, the SAC-2K has also been adapted for Emagic SoundDiver and Propellerhead Reason. Radikal says that SoundDiver allows you to assign SAC-2K controls to elements of supported synthesizers by simple drag-and-drop operations.

According to Radikal, support for additional applications is in various stages of development and is forthcoming for Cakewalk Sonar, Tascam GigaStudio, Sonic Foundry Acid and Vegas, TC Works Spark, BIAS Deck, and Ableton Live. Also in the works is support for systems from Pyramix, Soundscape, WaveFrame, and E-mu Paris.

Support will likely continue to grow and develop — Pro Tools support has already gone through multiple revisions — and keeping up with those changes will require a bit of homework. The reward is enhanced functionality and more efficient means to control your mixes. If the Pro Tools and Digital Performer manuals are an indication of what's to come for other programs, the SAC-2K's future is bright indeed.


The nature of control surfaces dictates that although the SAC-2K might work perfectly well in one environment, its performance may vary in another. When I used Digital Performer with a Pro Tools TDM system, for example, the SAC-2K had minor problems with the TDM plug-ins. Although I could select presets normally, the name of the preset often didn't update properly on the SAC-2K's display. More limiting is the fact that I couldn't directly edit effects parameters with the SAC-2K, as Channel Strip mode apparently doesn't work with TDM effects. (Radikal insists that it should work, but no matter how hard I tried, I had no success.) When I switched from Digidesign Audio Engine (DAE) to MOTU Audio System (MAS) mode, the host-based plug-ins were far more cooperative, updating presets and allowing full parameter editing.

While controlling faders in a group, I noticed that when I moved a fader quickly, the others had a tendency to lag slightly. A glance at the computer screen showed me that the only delay was in the updating of the physical controls; the onscreen faders moved in perfect unison. During playback the physical faders behaved as one.

Probably the greatest restriction in working with the SAC-2K is its limited support for selecting and editing audio and MIDI data. Because support for the SAC-2K depends entirely on the music-software developers, though, the problem is out of Radikal's control. For example, though standard Pro Tools commands such as Cut, Capture, and Separate have dedicated buttons, you can select data only by setting markers on the fly during playback; I'd rather be able to set and adjust markers while scrubbing. Zoom buttons are active only when the Zoomer tool is selected, which decreases their utility. Digital Performer's support for edit functions is better, allowing you to set markers in any transport mode. In general, though, I would like to see software vendors develop better support for edit functions.


Your assessment of the SAC-2K's value will probably depend on your frame of reference. If you're looking for most of the functionality of a Digidesign Pro Control for a bare fraction of the price, you'll regard the SAC-2K as a tremendous bargain. If you're doing a cost-versus-feature comparison with a CM Automation Motor Mix, however, you may think the SAC-2K is a bit pricey. Anyone looking to upgrade from a basic system such as a Tascam US-428 should do a dollars-to-drool analysis to justify the purchase.

The SAC-2K fits nicely into a midrange position among tactile interfaces. It looks right at home in any studio, without taking up too much space. It's just as comfortable with Macs as it is with PCs, and as soon as its USB issues are resolved, it will be expandable to boot.

As they would with any control surface, users should evaluate the level of support available for their favorite applications. With the roster of programs already onboard or under development, you'll probably find reasons to like the SAC-2K. In time I hope that all the documentation rises to the level of the Pro Tools and Digital Performer manuals and that Radikal produces additional application-specific function templates to lay over the buttons.

The more editing I can do from a control surface, the happier I'll be. When I no longer have to touch that rodent next to my computer, I'll probably forget the address to which I'm supposed to return the SAC-2K.

Brian Smithersis associate course director of MIDI at Full Sail Real World Education in Winter Park, Florida. You can reach him through his Web site,http://members.aol.com/notebooks1.


Radikal Technologies
SAC-2K Software Assigned Controller control surface $1,849



PROS: Professional appearance and function. Motorized faders with adjustable touch sensitivity. Excellent displays provide feedback. Good support for popular audio sequencers and software synthesizers.

CONS: Documentation is a work in progress. Usefulness of control surface with a given application is dependent on software developers.


Radikal Technologies
tel. (201) 836-5116
e-mail rick@radikaltechnologies.com
Web www.radikaltechnologies.com

SAC-2K Specifications Faders(9) touch-sensitive, motorized 100 mmKnobs(12) rotary encoders with 31-segment LED ringsTransport Controlsrewind, fast-forward, stop, play, record; (1) Jog wheelTrack Buttons(9) Track Select; (8) Mute/SoloSoftware-Assignable Buttons(43) organized into three clusters: Mixer mode, Channel Strip mode, software navigation/numeric functionDisplays(3) 2 × 40-character LEDs; SMPTE/locator readoutPorts(1) USB; (1) 4-port USB hub; MIDI In, Out, Thru; (1) 10 VDCDimensions24.50" (W) × 3.75" (H) × 13.75" (D)Weight22 lb. (shipping weight)