Sonic LAB: KMI K-Mix Mixer Review

US Digital mixer, audio interface and MIDI controller      15/09/16
    MP4 17:38 mins    

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Keith McMillen Instruments strike again with another of their highly functional pieces of gear. The K-Mix is a jack of all trades and as it happens, master of many.


First up it's a compact 8 input, 10 output digital mixer with 12 scene memories, on board DSP for EQ, Compressor, Gate and Reverb, it's also an 8 in, 10 out USB audio interface capable of 24-bit 96kHz operation. Add to that it's ability to function as a three layer MIDI control device, surround sound mixer with separate subwoofer crossover and we're about covering it. It's all controlled via the 9 KMI touch strip faders with LED backlight, 4 rotary pads (backlit too) and a myriad of buttons and function controls.


So, inputs start with a pair of KMI's own design mic pre's on CH 1+2 combi inputs, also capable of taking Hi-Z - instrument inputs, the next six ins are TRS jack. All have AKM A to D convertors.

Any or all of these inputs can be set to phono level or turntable (record deck) RIAA balanced inputs too.

Outputs The outputs are all balanced TRS with the exception of 9+10 which can be configured to use the 1/8th inch headphone jack output. Which normally functions as a monitor for solo and main outputs


All input channels have EQ, Compressor, and Gate DSP processing available, 3 stereo AUX sends (these go to outputs 3-8) plus a reverb send to the on board reverb.

Additionally you can process the stereo bus with EQ/Gate/Comp too.


Power is supplied via one of the two USB ports, micro and mini type, the Audio port will connect as a single wire to the host DAW for full class-compliant communication, while the second acts as a power only (you can hook up a basic USB power supply) or as a host for the KMI MIDI Expander (available separately) for adding MIDI io to the mix.

That's the thing, the K-Mix can operate in standalone mode too, working as a basic Mixer with discrete AUX sends and MIDI control.

But lets rewind and talk about the mic amps - in the review we put one of our SE Electronics Voodo VR-1 ribbons into an input and found it to be able to cope with the high gain required - no noise, clean sound and actually pretty sweet EQ gate and compression - no complaints there. The reverb helps add a some ambience, and doesn't sound bad, but it's not a Lexicon.

USB record path can be Pre or Post for each input - Pre gives you the input just after the A-D and input gain, and Post comes after the channel strip - so you can record clean or EQ/com/gate. This is switchable per channel.

USB returns - each of the 8 inputs can be routed Pre/Post, pre will take DAW returns 1&2 and sum them to the stereo bus, with no other control, additional pairs of outputs 3/4, 5/6, 7/8 will appear at the mixer hardware outputs. This also means that the analog input channels will still function as normal.

Pre Mode, (again selectable  per channel in software editor only) routes each the USB return through the channel fader and DSP but will sacrifice the analog input channel.

Unfortunately, these configurations are only globally saved, you can't store them per preset which is a shame, hopefully something that can be addressed in firmware.

MIDI control - out of the box (a rather swanky bit of packaging I might add), the KMI diamond - four multi-mode buttons, in Main mode, gives you basic Mackie control transport, stop, play, rew and rec, an additional three layers or banks of assignable MIDI control turns the faders and knobs into assignable MIDI CC (each bank with separate global MIDI ch), the buttons all send note values only (again with three global MIDI channels.)

I was hoping to see a proper Mackie Control mode where the faders would work in banks of 8 but thats apparently coming in firmware.

In operation

Mute and Solo are handled with the shift key and pressing the bottom of the fader(mute) or the top (solo), it's odd that the channel select buttons aren't used to mute as when in Main (mix) mode they don't do anything. However, when you want to edit EQ or Comp or Gate - done by selecting the rather small and hard to see dedicated mode buttons, they are used to select the channel you want to edit.

It just feels that the channel buttons are somewhat under utilised and could help with ease of operation. Not that the K-Mix is hard to use, it's just not as intuitive as it could be.

I should also add, that the LEDS on the faders and knobs are not terribly bright, in full daylight or high light levels its not always obvious what the metering or levels are, also the function/preset buttons are quite small, so you will need to be familiar with the layout if you are not 20/20 and expect to use in pressured situations.

Some features - channel input low cut (rumble filter), USB routings, and the rather nifty surround mix mode (5.1, 7.1) - you can route a subwoofer signal out of the headphones and set the cutoff freq -  are only accessible via the editor (Mac OS X, Windows). I would like to see a tablet/iOS version of this for those people who don't want to take a computer out with them, but the sheer amount of options available makes the K-Mix a veritable Swiss Army Knife, solving many common problems in a small footprint.

Overall, I was impressed with the K-Mix, I think most of my criticisms, if others agree with them could be fixed in firmware updates, something which KMI do regularly.

But for the mobile recordist, live mixing of elements, sub mixer, controllerist, this solves a lot of problems in one go. Another example of Keith McMillen's fertile design skills.

Available now £529/$579


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