FIG. 1: The Saffire Pro 24 DSP offers two Focusrite mic pres, a nice selection of I/O, and the company''s new Virtual Reference Monitoring technology.
One of the more recent developments in the portable audio-interface market has been the rise of units with built-in DSP chips. These mini-powerhouses of silicon processing are designed to offer zero-latency input monitoring with comfort effects such as reverb and compression, all without sapping power from the host computer''s processor.
Focusrite has joined this movement, upgrading its Saffire Pro 24 FireWire audio/MIDI interface to the new Saffire Pro 24 DSP. The new model adds a powerful onboard DSP chip, as well as a second discrete headphone mix, and Focusrite''s all-new Virtual Reference Monitoring (VRM) technology. You also get the software router/mixer, Saffire Mix Control. I found the half-rack-sized Pro 24 DSP to be a viable candidate for laptop producers called upon to track critical elements in less-than-ideal situations, offering solid performance and quality tones.
A Strong Foundation
The new DSP version builds on the solid design of the original Pro 24, offering 16 inputs and eight outputs. The Focusrite AD/DA conversion features supertight internal clocking via JetPLL jitter control to keep everything locked and in-focus. You get two channels of Focusrite FET-based microphone preamps with the same boutique performance found in the other Saffire products. The preamps are on analog channels 1 and 2 and offer front-mounted mic/line combo inputs with gain knobs and a +48V phantom-power-enable button (one button for both channels; see Fig. 1). Impedance settings are adjusted from within Saffire Mix Control. Analog channels 3 and 4 use ¼-inch rear inputs with switchable high/low gain from within the software.
FIG. 2: Despite the unit''s compact size, the rear panel offers plenty of I/O choices.
Other inputs include eight channels of ADAT Lightpipe optical and stereo S/PDIF on RCA jacks. Using Saffire Mix Control, the Optical input can also be switched to operate as S/PDIF inputs 3 and 4 for devices that need it; similarly, both the Optical port and the RCA outputs can be used to stream AC3-encoded 5.1 data to your external decoder. There are six rear-mounted ¼-inch analog outputs that will accept TRS or TS cables, MIDI In and Out ports, and a S/PDIF RCA stereo output (see Fig. 2).
Additionally, there are two discrete headphone outputs, each with its own ¼-inch stereo jack and volume knob. The front panel also offers 5-step LED input meters (-42dB, -18dB, -6dB, -3dB, 0dB) for each of the four analog inputs, and a monitor section with a volume knob and buttons for Dim and Mute, both of which I found immensely useful. The five front-panel knobs had a tightness to them that made the whole thing feel quite solid. There are also status LEDs for Power, FireWire (FW), and LKD, the latter indicating when the unit is locked to either its internal or external clock.
FIG. 3: Routing and application of DSP is controlled through the Saffire Mix Control software.
Control the Mix
Despite its sparse panel controls, the Pro 24 DSP is packed with features, most of which are adjusted within the powerful Saffire Mix Control software (see Fig. 3). You get complete routing flexibility over all 16 inputs, routing them into eight mono mix channels (or four stereo mixes, re-combinable on the fly). There is a Routing section with helpful presets and input settings, a detailed monitoring section with control over all six outputs and flexible presets for 5.1 setups and more, plus complete onboard reverb integration into all the mixes and outputs with Size, Damping, and Pre-Filter knobs. However, Saffire Mix Control ups the ante with two powerful features that set it apart among drivers for other devices in its category.
First is the Loopback channel, which can take any of the Saffire''s physical or virtual inputs (including Internet streams and outputs from a DAW) and route them to inputs 15/16, allowing reliably clocked inter-application audio that is much more flexible and less processor-intensive than using ReWire or Soundflower. I''ve not found a more reliable and simple method for grabbing audio clips from online streams or movie players directly into my DAW.
The second impressive feature is the Input FX channel that offers compressor and EQ plug-ins on the analog input 1/2 channels (the mic pres), even when in zero-latency monitoring mode and without requiring any processing power from the host CPU. Both plug-ins are modeled on classic Focusrite hardware and can be enabled/disabled for monitoring and recording separately—great for those times when you really like the sound you''re getting in the headphones and want to capture it to tape.
Power to Spare
The bottom left of the Saffire Mix Control window provides access to the Routing section and the input FX controls using the input FX button dropdown. This also enables the VRM, which is a bit like the reverse of Mic Modeler: It models listening situations and the effect of listening to your mixes on a variety of studio monitors (see sidebar “Listening in Virtual Spaces” for more about this).
The Monitoring section at the bottom right of the software window offers a large volume knob that corresponds to the physical Monitor Volume knob on the unit, along with the physical Mute and Dim buttons. The six color-coded, numbered buttons above represent which outputs are controlled by the knob (blue), which are muted (red), and which are set to their max output and not controlled by the knob (gray). It should also be noted that all settings, routings, mixes, and effects can be simply saved from the File menu to a convenient .pro24v file, which can be reloaded at will.
Another feature enabled by the onboard DSP chip is the ability to operate in standalone mode without a host computer. The Save To Hardware command in the File menu will print your current mix to the chip. When restarted without a host, the unit will operate with whatever routing and settings (including sample rate, digital sync, input effects settings, VRM, or anything else) were present when you initiated the command. This is extremely useful in many different situations, including when using the Pro 24 DSP as a routing matrix, a standalone analog or digital mic preamp, a standalone AD/DA converter, or even as a practice tool. To make things more flexible, the control software now supports connecting multiple Saffire units to a single host with shared sync and more. Though they cannot share a single zero-latency mix, they are able to operate at zero latency independently while working together.
I was happy with both the quality of the sound and the quality of build: sturdy enough for me to put it in my travel bag without fear of serious damage but with the quality converters, mic pres, steady clocking, and connectivity that I would want to do actual tracking. The package also includes the collection of great Focusrite VST plug-ins, as well as Ableton Live Lite and several loop banks. At first, I thought the addition of the DSP chip would be a bit of a gimmick, but it certainly proved me wrong in application; now I''m not sure I''d consider buying a unit that didn''t have one. Either way, I think Focusrite has done a great job combining the usability features into a small package that really delivers high-quality sound for professional tracking.
FIG. A: One of the virtual spaces offered is Virtual Bedroom Studio. Note the pulldown list of monitor types.
Listening in Virtual Spaces
The Saffire Pro 24 DSP is the first Focusrite product to feature the company''s new Virtual Reference Monitoring (VRM) technology, which aims to offer the experience of listening to speakers in a room environment through headphones. The concept is similar to a hybrid of Antares''
Mic Modeler and a convolution reverb. The designers used reference microphones to map the 3-D frequency output of a multitude of monitor types. Then they combined it with computer models of various listening environments (furniture, reflections, etc.) and sealed it with a human head model that re-creates how sound hits our ears.
You must be wearing headphones for the effect to work; it''s not designed to function through speakers. Once enabled, VRM offers three Room Models—Professional Studio, Bedroom Studio (see Fig. A), and Living Room—each with a selection of modeled studio monitors from a master list. Actual models aren''t given in the UI, but the manual lists them as ADAM, Alesis, Auratone, Creative, Genelec, Goodmans, KEF, KRK, Phocus, Quested, Rogers, Sterling, and Yamaha. Each room model offers several Listening Positions (i.e. Centre @ 1.65m from speakers, or 1.2m back and 45cm right, etc.).
VRM''s accuracy is impossible to gauge. It''s really more like an interesting reference tool. I''m not sure I could say that it really made me feel like I was sitting in the room listening to the speakers that I selected, but could definitely hear the timbre and tone changes as I surfed between them.
I enjoyed having the option of switching over to VRM as I was working to check my mix in different-sounding spaces, and I got the feeling that I was hearing about what it might sound like to suddenly have switched over to a flatscreen TV in the living room from the Genelecs in the professional studio, then to the KRKs in the bedroom studio. But I wouldn''t try to balance compressors or EQs on a critical mix while VRM was enabled; it is more of a reference-check tool, which I believe is what the designers intended. Either way, it''s the infancy of what will hopefully become a really useful headphone mixing option in the future, and something that curious producers should take the time to test for themselves.
Asher Fulero is a pianist/keyboardist and tech-savvy electronic music producer with a long résumé and endorsements from Moog and Nord. Visit asherfulero.com to hear his newest independent release,
The Green Piano.
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