Avid Mbox Pro

This one took me by surprise.
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By Craig Anderton

The Mbox Mini (top) and Mbox (middle) are more compact and less expensive, but both have the same sound and build quality as the Mbox Pro (bottom).

This one took me by surprise. Avid had been claiming their new Mbox series was “really good, really it is, it really isn’t like the old interfaces, honest” . . . which of course I took with a grain of salt. That is, until I put one on the test bench.

The Mbox Pro is an eight-in/eight-out FireWire interface. Two of the four combo jacks are switchable between instrument inputs on the front panel and line-level 1/4" ins on the rear. The other two are switchable on the front panel for mic or line-level signals. As a helpful bonus, these four inputs also have rear-panel TRS insert jacks. For the remaining I/O, inputs 5 and 6 are RCA auxiliary ins (but note that they aren’t turntable-friendly), and 7 and 8 are stereo S/PDIF. Th ere are six 1/4" balanced output jacks (enough for 5.1 surround monitoring), stereo S/PDIF out, and dual stereo headphone outs.

What’s not to like? The 48-volt phantom power switch is global— either it’s active for all four mic inputs, or it’s not. Also, the MIDI and S/PDIF are on a breakout cable. Interestingly, on the one-model-down Mbox (which has less I/O and uses USB2, and also sounds excellent), the MIDI and S/PDIF jacks are on the unit itself.

If you care about specs, they’re extremely impressive, with audible results. Low-frequency response rolls off by less than 0.5dB at 5Hz—that’s serious low end—and even at a sample rate of 44.1kHz, response is essentially flat up to 20kHz, after which it falls off a cliff . There are no noise components above –120dB, and most sit around –130dB. That’s seriously quiet. As to distortion, all I could find was a second harmonic distortion component at –110dB, and a third harmonic at a hair over –100dB. Short version: These specs are audiophile-quality and very few interfaces meet them.

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Rear Panel

What’s more, the thing is built like a tank. When you take off the outside metal case, there’s an inside metal case. We’re talking major shielding. There’s also a feature that only us geeks notice, but it really matters: Jacks and controls mount to the panel with lock-washers and nuts. This is very different from inexpensive interfaces that solder these components right onto the circuit board and have the shaft spoke out through a hole in the casing, wobbly knobs and all. If you’re plugging and unplugging a lot, Avid’s way of doing it takes strain off the circuit board, greatly adding to longevity.

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It’s not an overstatement to say I was shocked by the quality of the new Mbox Pro and the line overall. Granted, it’s not cheap, but you do get a significant break if you buy any Mbox bundled with Pro Tools 9, which costs $599 by itself. Whichever new Mbox you choose, that bundle is certainly a Key Buy-winning value.


PROS Specs and audio quality are nothing short of superb, and more in the league of expensive standalone converters. Extremely durable construction.

CONS Phantom power is global, not selectable per mic input. No turntable inputs.

PRICE Hardware only | List: $799 | Approx. street: $720
With Pro Tools 9 | List: $1,099 | Approx. street: $1,000