Reprinted from the June 2009 issue of Church Production Magazine
Audio Product Review: DiGiCo SD8 Audio Mixing Console
There was a time in the not-so-distant past when live sound engineers viewed digital consoles with a very healthy measure of skepticism. Perhaps these concerns arose from having been bitten one too many times by a mixer that capriciously decided to throw every mic on stage wide open while the engineer was 100 feet away and couldn’t grab the master. Or maybe a major computer crash 20 seconds before curtain ruined just one too many days. And in those early days, the uncertainty in digital consoles wasn’t always founded in such extreme calamities. We all grew up with at least a fader, pan pot and mute switch for each channel, and we all had an initial moment of befuddlement—“how do I mix 48 channels with only eight faders?”—and that befuddlement actually dissolved into some disdain even after we used these mixers for a while.
Fast-forward to the present. We have learned to live with fewer faders than channels, and the manufacturers have tried to meet us in the middle with control surfaces that feel a lot more conventional. And now we all nod and agree that life would be very difficult without snapshots and plug-ins. We believe in digital mixers, and there are some awesome digital mixers available. UK-based DiGiCo has introduced its SD8, an addition to a line that includes the popular D1 and D5, and more recently, the SD7. The SD8 is a sophisticated console that touts some pretty nice features. I recently got up close and personal with one and learned a lot about it.
Dissection of an SD8
Internally, the SD8 handles all processing with “Super FPGA” floating point processing—a feature not found in any other console under $50,000, except Digico’s own SD7 model. The mathematical precision facilitated by floating point processing creates massive headroom and vastly improves the quality of the sound over fixed point processing, and it does make a huge difference. Mathematically, floating point processing facilitates insane amounts of headroom—in the thousands of dB—making clipping virtually impossible (inside the console that is—once the signal returns to the “real world” it can certainly clip and distort). But the more important thing is the internal mathematical precision of floating point processing: it simply renders a much higher quality audio signal. Floating point precision is standard on consoles that cost substantially more money, so a key part of the story here is that DiGiCo provides it in a sub-$50K console.
The SD8 has 60 stereo or mono channels available (the equivalent of 120 channels of DSP)—plenty for most churches—and certain key functions are available on all channels all the time, in contrast with some digital consoles that don’t offer consistent processing on all channels. Specifically, each channel sports a compressor, gate, four-band parametric EQ, 24-dB, high-pass and low-pass filters, and up to 1.3 seconds of delay. The console’s user interface features 37 motorized faders, which felt great to the touch—very smooth and solid. One particularly slick fader convention is the “center detent” that DiGiCo’s engineers have achieved. When the faders are used as controls for one of the console’s 12 included graphic equalizers, they have this detent at mid-scale, just like the physical graphic EQs we’ve come to know and love. This is accomplished with the faders’ servomotors, and is an excellent example of the detail that DiGiCo devoted to the user interface.
The faders are assignable in banks of 12 as channels or masters, As a matter of fact, fader assignment is very flexible, literally enabling the assignment of any channel, bus or group to any fader—there is no requirement for adjacent, sequential assignment. The center bank of 12 faders is situated under the console’s touch screen, in keeping with DiGiCo’s tradition of using the touch screen to simulate the real channel strip of an analog console. A second layer is available to double the functionality of the control surface, and to customize the console nicely to the user’s wishes. Each fader has an electronic scribble strip for naming channels, buses and groups.
The console’s 15-inch TFT LCD backlit touch screen is indeed central to its operation, and is a key feature that would attract me to consider this console. It exhibits very high resolution, and uses color extensively to provide rich information that informs the operator at a glance. This display would be marvelous if it only presented visual information, but the fact that it is also a touch screen really makes it incredibly valuable. In addition to the on-board screen, an SVGA output facilitates the connection of another monitor to provide an external overview—also very nice.
Numerous rotary encoders on the control surface are assignable, and others are dedicated. In particular, the knobs to the right of the touch screen are dedicated to the function of a channel strip, again keeping with the DiGiCo tradition of creating the feel of a full analog channel strip. The assignable knobs can be quickly and easily assigned to the auxiliaries, for instance, and DiGiCo employs a very clever mechanism for scrolling up and down through the channel strip with two buttons. In addition to the soft controls associated with the faders, there are control sections for automation, snapshot, monitoring, headphones, FOH monitor speaker selection, talkback mic and control of macros. One other user interface segment provides control over the console’s two solo buses—very handy for separate monitoring of in-ear mixes vs. wedge mixes. The solo buses can be established as mono, stereo, PFL (pre-fade listen), AFL (after-fade listen), or solo-in-place, so the dual buses could also be set up as AFL and PFL, for instance. I really like that flexibility.
The SD8 features 24 stereo solo and master buses that can be allocated to accommodate exactly what is necessary for the application. This facilitates numerous auxiliaries for stage monitoring and effects. The console also sports 12 graphic equalizers that can be assigned to any channel or bus, and 12 VCA control groups are also available. There are six stereo effects processors available as well, including reverbs, delays and others. The console’s outputs can be routed in a 12x12 matrix, which nicely facilitates the feeding of cry rooms or other such signal destinations.
Rear Panel Rundown
The rear panel of the console features bays for its two hot-swappable power supplies—a very nice plus to ensure uninterrupted performance in the case of a failure. Both BNC and AES word clock sync I/O is also found on the panel, along with MADI I/O for connection with the stage and a split for recording. The console ships with the SD8 MaDiRack stage box, which features 48 mic inputs and eight additional analog inputs. A 100-meter MADI snake is also included.
The unit I evaluated used a third-party MADI interface facilitating recording with a DAW on a laptop computer, a space for which is thoughtfully included in the “northwest” corner of the control surface. In addition to the SVGA and other computer-oriented I/O, the rear panel also features local audio I/O, including four AES/EBU I/O pairs and eight analog I/O pairs in the form of XLR connectors. MIDI and RS-422 ports are also included. It’s nice to easily get signal out and back from old favorite rack gear at FOH.
This console is very well appointed in terms of signal processing and I/O, and its user interface is well planned and very accessible. The audio quality, too, is truly excellent, due to the incorporation of floating point precision. Considering these things, this console is a very good value for the money, and I’d definitely recommend taking a look at it.
John McJunkin is the CEO of Avalon Podcasting in Chandler, Arizona, which offers high quality podcast production and consultation services to a broad range of clients. He’s also the host of the Podcast Pro Tech & Tips Podcast at www.avalonpodcasting.com.