by Craig Anderton
Focusrite has garnered quite the reputation over the years for their interfaces, but they’ve been branching out lately. Harmony Central did a Pro Review of their Pro 24 DSP Audio Interface with VRM, a novel interface with VRM (Virtual Reference Monitoring) that simulates listening to speakers while using headphones. We also covered the stand-alone VRM Box, which brought VRM technology to add-on hardware that worked with any interface.
With the Scarlett line, Focusrite has made another departure—into the world of USB 2.0 interfaces. Most of their interfaces have been FireWire, with the occasional foray into budget-oriented USB 1.0 interfaces with limited I/O. But it seems the handwriting is on the wall for FireWire, as fewer computers include it, and several companies—not just Focusrite—are producing USB 2.0 interfaces. Of course, FireWire isn’t going away any time soon, but Focusrite’s decision to launch a USB 2.0 line of interfaces underscores its emergence as a popular, valid, and reliable standard for audio work.
However, note that the USB bus doesn’t supply enough power to run the 18i6, so forget about bus power. The package includes an AC adapter and in a considerate touch, three different detachable plugs (US, Euro, and UK) as befits its global specs—100-240V, 50/60Hz.
As for compatibility, the 18i6 runs on Mac OS Snow Leopard 10.6.5 or higher and Lion. For Windows, the options are 32-bit Windows Vista/XP3 or 32/64-bit Windows 7. The Scarlett MixControl application is virtually identical to the Saffire-style MixControl, and serves as your system’s traffic director. (Note that unlike some other Focusrite interfaces, there’s no internal DSP-based signal processing.) Thanks to using USB 2.0, 96kHz operation is supported when using all inputs except of course when using the ADAT in, which is limited to 48kHz.
The Scarlett 18i6 is clearly targeted toward studios that need lots of inputs for tracking, and aren’t overly concerned with multiple outputs for monitoring. The complement of 18 inputs includes the following.
Two front panel mic pres with balanced combo jacks. They automatically switch between line and mic inputs depending on what’s plugged in, but can also be set to DI (instrument) input via the software mixer application—more on this later. An indicator light shows whether an input is set to instrument mode so at least you don’t need to boot up a computer to see the setting. Phantom power is switchable to both inputs simultaneously; I measured it as 43.4V. While not 48V, few—if any—condenser mics will care about the slightly lower voltage.
The rear panel has six balanced line ins using 1/4” jacks, coaxial S/PDIF I/O, and ADAT optical input. This is clearly designed for those who want to expand the number of mic pres with one of the many rack devices that offers eight mic pres terminating in an ADAT optical output. Note that this is input only; there’s no ADAT out.
Speaking of outs, the six outputs is correct, but somewhat optimistic. There are two main monitor outs (1/4” balanced line), with two more outs from S/PDIF coax and two more via a front-panel headphone jack.
Finally, I’ll applaud Focusrite (as I always do) for including 5-pin DIN MIDI I/O physical connectors. Sure, more and more devices do USB-over-MIDI, but there are plenty of hardware MIDI boxes that want to talk to your computer, and the 18i6 will let you do that.
The main software is the Scarlett MixControl application, which is a Scarlett-specific variation on the Saffire line’s MixControl. One of the Scarlett differences compared to other Focusrite interfaces is that there’s no onboard DSP processing.
Although not essential to operation, you do get some other software goodies like the Scarlett VST/AU plug-in suite with Compression, EQ, Gate, and synthesized (as opposed to convolution) Reverb. These provide a useful alternative to equivalent plug-ins you may already have, and they’re quite efficient so you can sprinkle them liberally amongst your tracks. Check ’em out.
Furthermore, you get a lite version of Ableton Live, a full version of the Novation BassStation plug-in, and over 1GB of samples from Loopmasters. While these add-ons will likely not be the deciding factor in whether or not the 18i6 is for you, they do add value.
With its emphasis on DAW integration, monitoring becomes an important consideration. You have two main template options for the MixControl, one for Zero Latency tracking (routes a monitor mix of the various inputs to the main monitor and headphones outs), and DAW Tracking that allows monitoring input channels through your DAW—essential if you need to monitor through plug-ins, assuming your computer is fast enough to minimize latency.
Audio performance is excellent, as we’ll see from the following tests (taken at a 44.1kHz sample rate).
Frequency response was down -0.5dB at 20kHz and 15Hz, and -3dB at 5Hz.
The A-weighted noise level was below -120 down to 5Hz, and mostly hovered around -125dB.
The THD distortion products were below -115dB at 2kHz and -108dB at 3kHz, but look closely at the screen shot: the other distortion products are difficult to differentiate from the noise floor. That’s quite impressive.
Intermodulation distortion specs were equally good. The distortion products at 120 and 180Hz were well under -110dB, and the high-frequency ones were pretty much buried in the noise floor.
Stereo crosstalk was below -84dB up to about 1kHz, where it started rising until it hit around -55dB at 20kHz. I’ve definitely measured better, but -55dB is acceptable, especially as it doesn’t that much crosstalk until frequencies that most people can’t hear anyway.
Subjectively, the preamps follow the usual Focusrite recipe by eschewing “character” and instead going for definition. Throw some mics on an acoustic guitar, and you’ll appreciate that as long as the mics can preserve the transients and crispness, so will the 18i6.
FireWire interfaces give slightly better throughput for big projects at high sample rates compared to USB 2.0, but for most applications, the difference isn’t going to be significant. Those who find FireWire squirrely, or are using a computer that doesn’t have the “recommended” FireWire chip set, are surely happy to see the USB 2.0 spec coming on strong—and with the 18i6, Focusrite has successfully “ported” the ingredients in their FireWire interfaces to the world of USB 2.0.
Craig Anderton is Executive Editor of Electronic Musician magazine. He has played on, mixed, or produced over 20 major label releases (as well as mastered over a hundred tracks for various musicians), and written over a thousand articles for magazines like Guitar Player, Keyboard, Sound on Sound (UK), and Sound + Recording (Germany). He has also lectured on technology and the arts in 38 states, 10 countries, and three languages.