CME U6MIDI Pro vs iConnectivity mioXM

The CME U6MIDI Pro is what you reach for once one MIDI cable stops being enough. It packs 3 in / 3 out of 5-pin routing behind a single USB-C port, built as a standalone router rather than a plain pass-through interface.

Split, thru, merge and filtering are configured through CME's free UxMIDI Tools software for Mac and Windows, and the box passes MPE, sysex, MIDI timecode and clock alongside ordinary notes and controllers, so it holds up behind synths and controllers that lean on those messages. A high-speed optocoupler keeps the signal clean between ports.

The catch is that the configuration lives entirely in software, so there is nothing to see or adjust on the box itself once it is set. Three ports is also a ceiling, fine for a small rig, tight the moment a fourth piece of gear shows up. It has a shorter Amazon track record than the budget pick, with under a thousand reviews so far.

The iConnectivity mioXM is a routing hub for a studio, not an interface for one synth. 4 in / 4 out of 5-pin DIN pairs with 4 USB-MIDI host ports and an Ethernet RTP-MIDI network port, so DIN gear, USB gear and networked computers all land in the same box.

The Ethernet MIDI networking is the real feature: 12 virtual network ports can be assigned across the DIN, USB and networked connections, which gets around the USB cable-length and port-count limits that force smaller interfaces to sit right next to the computer. A capacitive touch panel stores up to four user-definable presets, and class-compliant USB devices need no drivers.

None of that is free. At roughly five times the budget pick's price and 3.4 pounds in a full-size box, it is built for a rig with real routing to do, not a single keyboard. Buying it for one synth means paying for ports that never get used.