Mbox Mini (2 x 2): $299 street
Mbox (4 x 4): $499 street
by Craig Anderton
For years, many audio interface aficionados considered the Mbox line as basically a “dongle” for Pro Tools users who couldn’t afford the HD systems. The audio quality was acceptable, but lagged behind the state of the art. Although Avid (Digidesign at the time) introduced an improved second generation, by that time the world had moved on again, and even the second generation just wasn’t up to the standards of the day.
So you can probably understand why, when Avid announced the third generation Mbox series, I wasn’t exactly tingling with excitement and expected more of the same. But that started to change when the company approached me about doing a Pro Review for Harmony Central. I said that probably wasn’t a good idea, because I already had some degree of bias about the Mbox and maybe they’d want to find someone more open-minded. Yet they basically insisted I check it out, and they were willing to let the chips fall where they may . . . “really, Craig, this generation is different, we did our homework.” Sure. Ever hear a marketing department say “Really, Craig, this really doesn’t sound all that great, but I’m paid to say it’s good”?
In hindsight, I suspect they targeted someone who was on record as not being a fan of the original just so that if I liked it, they could say “See? Even this guy likes the new Mboxes!” In any event I went ahead, and did an in-depth Pro Review on their top-of-the-line third generation interface, the FireWire-based Mbox Pro. To my surprise, the specs weren’t just great, but stunning—and confirmed what my ears were hearing in terms of quality. I also checked out the less expensive, 4 x 4 Mbox (USB 2.0 bus-powered, up to 24-bit/96kHz); while the specs were just a teeny smidgen off compared to the Mbox Pro, they were still exceptional.
Furthermore, the construction was exemplary, with superb shielding and quality components. I’ve rarely seen a company update a line so radically, or to such good effect. What’s more, all Mboxes are cross-platform, and have efficient, low-latency drivers that work with DAWs other than Pro Tools (and very well, I might add).
So when Avid released the 2 x 2 Mbox Mini (USB 1.1 bus-powered, up to 24-bit/48kHz sample rate) my first question was how it would compare to the flagship Mbox Pro. Once more, I was shocked. Sure, it’s much less expensive, but it still comes really close to performance level of the other two interfaces. (Note: This review of the two bundles concentrates with the one based around the Mbox Mini, as Phil O'Keefe already did a review of the Mbox when it first appeared.)
The Mbox Mini package (Fig. 1) comes with the interface itself, a USB cable (the Mbox and Mbox Mini are both USB-powered and don’t require an adapter), a CD-ROM with audio device drivers (of course, check the web site first for an updated version so the CD-ROM can take its rightful place as a beverage coaster), quick start guide, and product registration card. The Mbox is the same, except of course for the interface. Either bundle includes an iLok 2. One Mbox feature not found in the Mini is on-board reverb DSP for monitoring.
Fig. 1: The Mbox and Mbox Mini bundles include Pro Tools Express, but note that the drivers work with pretty much any DAW.
However, in addition to the hardware-related aspects, there’s also a copy of Pro Tools Express. We’ll get into this later, but let’s continue on with the interfaces.
Fig. 2 shows a top view of the Mbox Mini. Note the solid, wrap-around metal construction (the outside exoskeleton is not plastic). Also, note that these pictures are of the Mbox Mini; photos of the Mbox are included in the Pro Review of the Mbox Pro.
Fig. 2: Mbox Mini top view.
In Fig. 3, note that there’s additional shielding within the metal outside. These are very “clean” units in terms of not generating RF into your studio.
Fig. 3: Mbox Mini with the wrap-around metal cover removed.
And because I like taking shots of the insides of pieces of gear, what the heck . . . here’s two of them (Fig. 4).
Fig. 4: Two shots of the Mbox Mini’s insides. In the bottom shot, the large object to the right is the XLR+1/4" combo jack.
For example, I measured noise on the Pro at a maximum of -120dB, and for THD, the 2nd and 3rd harmonic distortion products sit at -110dB, with no other significant distortion. Intermodulation distortion is virtually non-existent, with no distortion products much above -120dB. Crosstalk averages around -96dB. I don’t mean to get all geeky on you, but the geeks will realize just how good these specs are.
Now check out the noise figures for the Mini and Mbox (Fig. 5).
Fig. 5: Noise performance for the Mini (top) and Mbox (below).
The performance for the two is pretty similar, with a very slight advantage going to the Mbox; while the noise hits -115dB max, it sits mostly below -120dB. This is particularly surprising for the Mini; now let’s turn our attention to the THD (Total Harmonic Distortion; see Fig. 6). The Mini’s 2nd and 3rd harmonic distortion products max out at -100dB, with the Mbox hitting about -107dB.
Fig. 6: The THD specs are also impressive. The top spec shows the Mini, and the bottom, the Mbox.
The Mini’s intermodulation distortion has two distortion products at around -110dB, with the Mbox having one visible distortion product at -110dB (Fig. 7).
Fig. 7: Intermodulation distortion for the Mini (top) is just a little bit less impressive than for the Mbox (bottom).
The spec that surprised me the most was crosstalk (Fig. 8). Crosstalk on the Mini averages around -90dB, and on the Mbox, around -95dB. These figures aren’t just good; they’re exceptional. This is where many interfaces seem to cut corners, as crosstalk specs of 70dB or even 50-60dB at higher frequencies are not uncommon. The cross-channel separation means that any stereo imaging is maintained well.
Fig. 8: The channel crosstalk specs for both are excellent, although the Mbox Mini (top) has a shade more crosstalk than the Mbox (bottom).
And I almost forgot about frequency response, because these days, all interfaces are pretty much equal in that respect. However, the Mbox and Mbox Mini go the extra—or perhaps more appropriately—thye extra octave, by being down only 0.5dB at 10Hz (Fig. 9).
Fig. 9: Frequency response specs for the Mbox Mini (top) and Mbox (bottom).
The bottom line to this orgy of measurements it that there’s a solid technical reason why the audio sounds as clean and open as it does.
For I/O, the Mini is 2 x 2; one input has a combo mic/line in (with switchable phantom power) or 1/4” DI input, while the other has a 1/4” line/DI input. Note that phantom power is available (Fig. 10).
Fig. 10: The Mbox Mini rear panel.
What this means is that if you want to do stereo miking, the Mini is not the droid for you—unless you have an outboard preamp you can plug into the other line input. The Mini seems aimed more at the singer/songwriter studio environment, although the dual DI inputs allowing for something like electric bass with electric guitar, while two line inputs are ideal for keyboards and drum machines. The outputs are two 1/4” jacks. Note that there’s no MIDI I/O.
Front panel controls (Fig. 11) are two gain knobs (pull them up to enable a 20dB pad), master output, headphone jack, mute button, and input/playback mix control.
Fig. 11: The Mbox Mini front panel.
The Mbox ups the I/O to 4 x 4 (as mentioned previously, click here for images). Two channels of I/O are coax digital S/PDIF; two analog inputs have front-panel DI 1/4” jacks that can switch individually to rear-panel combo jacks for mic/line inputs (with switchable phantom power for the pair). There are also two 1/4” monitor outs, as well as 5-pin DIN MIDI in and out. Front panel controls are two gain knobs (again with pull-for-pad), headphone jack with volume control, master level, and Soft Limit buttons for the inputs (just like the Pro model). There are also buttons for monitoring in mono, and “dim” to reduce levels—wonderful if the phone rings. Furthermore, the Mbox has a useful mixer applet for signal routing, and takes advantage of onboard reverb that can be used while monitoring (great for singers who want to hear some reverb as they sing). The applet even offers a guitar tuner.
Pro Tools Express works only with the Mbox interfaces (not even other Avid interfaces) and is only sold as part of a bundle, but provides a free entry to Pro Tools, with a crossgrade path to the full version for $399. There are limits: 16 stereo (or mono) tracks, 16 MIDI tracks, 16 buses, no clip gain, and no Beat Detective—but it’s also notable for what is included (Fig. 12), like 30 different plug-ins (including three virtual instruments), compatibility with AAX, RTAS, and AudioSuite plug-ins, the excellent Elastic Time and Elastic Pitch for stretching/groove applications, Sibelius score editor, automatic delay compensation, export to iTunes and SoundCloud, DirectLink and HyperControl templates for M-Audio keyboards, track comping, MIDI editing, and more.
Fig. 12: Pro Tools is a highly functional, albeit "lite," version of Pro Tools.
There’s a helpful FAQ about Pro Tools Express on the Avid web site, so there’s no point in repeating that type of information here. There’s also a comparison chart that explains the differences among various versions of Pro Tools.
Pro Tools Express requires an iLok for operation but an iLok 2 comes with either bundle, which adds $50 to the bundle’s value.
Both bundles give you Pro Tools’ essential features, so aside from instruments and a Mac or Windows computer, you don’t need anything else to make music. If you eventually decide you need to upgrade to the full version, you’ll already be off to a solid start. “Express” version or not, few people will feel limited.
Regardless of what software you use, the star of either bundle has to be the exceptional audio quality and rugged construction of the Mbox interfaces. At these prices, achieving performance that’s within a whisker of the top-of-the-line Mbox Pro is noteworthy. The audio character of these interfaces truly deserves the term “pristine” that’s thrown around so loosely these days, and the specs definitely speak for themselves—but your ears will tell you what you really need to know.
Craig Anderton is Editor Emeritus of Harmony Central and 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.