Recording - April 2017 - 24

Keith McMillen
Instruments

K-Mix

Part digital mixer, part audio interface,
part control surface-100% next-generation
REVIEW BY MIKE METLAY

eith McMillen Instruments builds controllers that are genuinely unique in a me-too world. Thanks to the company's
touch-sensitive Smart Fabric, which replaces moving parts
like keys, faders, buttons, or knobs, KMI products are light
yet sturdy, very expressive, and highly affordable.
We've reviewed controllers by KMI before (the QuNexus in
December 2013 and the K-Board in June 2015), but the K-Mix is
something new: it's the company's first foray into handling audio. The
K-Mix combines a variety of technologies, both familiar and new, into
a compact package that's intended to serve multiple purposes in the
small studio or live rig.

Opening the package

The K-Mix is a slightly angled desktop box just a hair over 6" x 9"
in size. As you can see from the photo, there are no knobs, buttons,
faders, or other moving parts anywhere; all of the functions you'd
normally need to access are performed by backlit touch-sensitive
Smart Fabric controls. The front panel is entirely sealed, so the unit
is spill-proof. No more faders getting gummed up with dust or spilled
drinks, no more knobs getting snapped off or smashed down in transit
and cracking circuit boards... for that one feature alone,
anyone who gigs around should be looking at the K-Mix
and drooling! (Fortunately it's also drool-proof.)
The most obvious control surfaces are the nine faders and the four "rotaries", which provide fine-grained
24

RECORDING April 2017

control for all K-Mix functions. Each fader is backlit with multicolored
LEDs from green to red-with 12 LEDs per fader, visual resolution
isn't superfine, but is certainly good enough for conventional use. The
faders themselves are textured to provide quick and resistance-free
movement without stickiness or slipperiness when touched; they have
tiny indentations where they'd normally be set to unity gain, easy to
feel with a fingertip, and raised points at the top and bottom that serve
as guides to the Solo and Mute controls. As a result, you can mix
while listening to your audio or looking at your players without having
to look down at the K-Mix; you have the cues you need to mix by feel.
The rotaries are backlit with a ring of 16 red LEDs, and for most
purposes they act as dials, following circular motions of a fingertip.
(The one exception is Surround panning, which we'll discuss below.)
There's a "dead zone" at the bottom of each one, so they behave like
knobs rather than infinite encoders.
The Diamond Pad is used not only for transport controls in Mix
mode (where the four buttons send Mackie Control format transport
messages) and assignable MIDI messages in MIDI mode, but also to
select whether the unit's surface is controlling the audio mix or sending
one of three banks of MIDI messages; its green and red backlights
give good feedback on what's what.
The rest of the buttons are used to access specific pages of control
(e.g. Pan, Aux sends, or effects settings), or to select Presets. The K-Mix
can store 12 presets that include most routing and parameter settings
(A few are global for all Presets). Four buttons on the left are of particular importance: the Shift button accesses second functions on many
controls, the Bypass button turns off effects (and also acts as a shortcut
to reset controls to their default values, like unity gain on faders and
center position for panpots), the Fine button sets the faders and rotaries to perform fine adjustments around the current coarse settings,
and VU turns the faders into a handy meter bridge.
The rear panel is straightforward: eight inputs and eight outputs on
balanced 1/4" TRS jacks (except for inputs 1/2, which are XLR/TRS
combination jacks), plus the KMI-standard pair of USB connectors,
one Mini-B and one Micro-B. Either jack can power the unit from the
included wall wart for standalone use as a mixer; one also acts as
a USB connection to your computer, and the other connects to the
optional KMI MIDI Expander box for more generalized MIDI control
in your studio. A minijack for headphones on the front edge of the unit
completes the I/O.

As a mixer

The K-Mix is an 8-in/10-out mixer with a stereo Main bus and three
stereo Aux buses (individually settable pre- or post-fader). A built-in
Analog Devices SHARC processor provides the DSP horsepower for
mixing, routing, and onboard effects. On the analog side of things,
before the AKM A/D converters, the inputs are exceptionally clean.
The first two channels' proprietary µPre preamps are of special note:
built by KMI especially for the K-Mix, they're clear and very quiet,
with 60 dB of gain and suitable even for relatively finicky ribbon mics.
Phantom power is individually selectable with dedicated LED indicators on the front panel.

Table of Contents for the Digital Edition of Recording - April 2017