Why do you need a midi patch bay?

If you have more multitimbral synths and sound modules than you have multiport midi outs for, then you might use a midi patch bay. And if inspiration strikes when something is not connected and not easy to connect, you'll want to be prepared.

There are a few classic midi patch bays.

In the 80s there was the Kawai MAV8 used switches that could allow you to send one of the 4 midi inputs to any of the 8 midi outputs.

Also from the 80s was Digital Music Corp has a similar concept with the MX-8 but increased the number of midi inputs to 6 with 8 outs. But it could also process the midi signal with functions like velocity scaling, MIDI delay, transposing, patch changing, velocity cross switching, channel shifting and mapping. The front panel digital display allowed users to make these complex settings.

In the 90s we had the Opcode Studio 5LX was a 15 in, 15 out midi interface and patch bay. The hosted Mac software, OMS Setup apps could allow you to name the inputs after the instruments which would allow their names to appear in the Vision midi sequencing software. The Studio Patched app allows for many of the functions of the DMC MX-8 along with even more complex routing.

A few years ago Kenton announced the Interchanger which is a more modern take on Opcode's Studio Patches and DMC MX-8 but it seems it is still in development.

These midi patch bays offered a lot of features. But if you simply want to patch any 22 midi connections to any other connection without climbing behind your gear rack the the simple Signex CMP22M midi patch bay is all you need. With an 8 and 6 port midi interface such as MidiMan Midisport 8x8, Emagic Unitor 8, Opcode Studio 4, 64X, 64XTC, 128 or MIDIport 96, MOTU MIDI Express 128 or MIDI Express XT, or iConnectivity mioXL or mio10, or Alyseum AL-88C, ESI M8U or MU8XL you could connect all rear panel ins and outs (to the CMP22M and then you are left with 8 to 6 more connections for 3 or 4 modules that could be midi inputs.

For sending patch library data with software like Opcode Galaxy, MOTU Unisysn, Emagic SoundDiver, Coffeeshop PatchBase, or Sound Quest MidiQuest between a synth and a computer you usually need both the midi in and out connected. If you have a 8 in, 8 out midi interface and more than 3 or 4 modules you might need a 2nd CMP22M. Once you have this set you will never have to go behind your rack again, at least for midi connections.

And when your synths are not multitimbral you might consider a midi thru box. Midi Solutions, Erica Synths and Kenton make 4, 5, 8, and 25 port thru boxes. A thru box simply splits the same midi signals multiple midi din outputs.

Here is a tip: when you need a hardware thru or merge box close to you CMP22M you might mount a rackspace storage shelf on the outside of your rack. Here we use a 6 inch deep universal rack shelf with the front facing the CMP22M, and the rack screws hold both units in place. Here we store a Midi Solutions Thru and Blokkas Midi Hub within easy reach of our CMP22M.

Seismic Audio makes some great short midi cables in red and blue. We use them for connections to both the rear of the MidiMan Midisport 8x8 to the CMP22M as well as front panel patching.