I see in the Midihub Editor that you can configure a maximum of four logical USB devices (A to D).
Is there any reason the unit couldn’t support more than four USB devices? The USB standard allows the host to support up to 127 devices.
My use case is that I’d like to connect several MIDI controllers and several synths, more than four in total, all via USB.
Maybe this could be achieved by a firmware update or even just a change to the Editor?
The Midihub acts as a peripheral device, not a host. The USB ports within the Editor refer to the USB MIDI ports used for communication with the host.
You can connect multiple Midihubs to the same host.
Thanks for the quick reply, Giedrius.
I know the Midihub is a device rather than a host, sorry if I was unclear about that. What I meant was whether the Midihub firmware or the Editor would allow the Midihub to have more than four USB MIDI ports for communication with the host.
If you want a concrete use case, let’s say I have three USB MIDI controllers A, B, and C, and three USB MIDI synths D, E, and F. None of them have 5-pin DIN MIDI ports. They are all connected to a USB hub on my USB host (let’s say my computer), along with the Midihub (via its own USB cable). What I’d like to be able to do in the Editor is assign each of these six devices (A-F) their own separate USB “ports” A-F. Right now, I’m limited to four such ports, A-D. Could this limit be raised to 6 (or why not 127) by a change to the Editor or the firmware?
USB MIDI has a limit of 16 ports on a single endpoint, there’s probably some trickery possible if there’s more endpoints available to go above that. The Midihub is designed around the current limits though, so the amount of USB MIDI ports won’t be increased.
That said, there’s ways to use more than 4 USB controllers with Midihub - the host computer should merge the MIDI streams to a single Midihub port, each controller should be set up to use channels dedicated just for their use. Probably there’s software out there that could switch up the channels while merging the streams.
What is the OS your host computer uses? Or what device is hosting the USB MIDI devices?
I’d be happy if the Midihub could have 16 USB ports, that would be plenty for me.
I get what you’re saying about merging the streams on the host, that’s a workaround I could use, although my configiuration would be easier to understand and maintain if I could dedicate a port to each physical device. Would it be hard to add the other 12 ports to the Midihub?
As for my own config, I’m using a mini-sized Windows 12 computer as the host and I use MIDI-OX to connect my USB devices to the four virtual ports on the Midihub.
Yes, it would require changes from the ground up. 
Anyway, as you’re using the all mighty MIDI-OX, you can get it to remap the channels and merge the streams according to your needs, so you can have full access to more than 4 USB MIDI devices:
Here’s for example how you can define a Translation map of converting Ch. 1 messages to Ch. 2:
In Options → Data Mapping dialog:
Save it to a .oxm file. (best to save it to the default location at C:\Users\<Your User>\AppData\Local\VirtualStore\Program Files (x86)\MIDIOX)
Then if you right-click on the little rectangle in the MIDI Port Routing Window and go to Properties for a particular connection:
You can apply the map you just created:
See the MIDI-OX Help Contents for more details.
Phew! 2 x 16 = 32 Midihub options in Mac MIDI Patchbay would freak me out 
