DAW confused by multiple Midihubs

Unless my Midihubs are powered on after my DAW is running, they are not identified correctly.

My setup: Windows 10 laptop, 2 USB hubs, 4 Midihubs (2 in each USB hub), Presonus Studio One Pro 5.3, editor and Midihubs updated recently. In the device manager, each Midihub shows up on a different “COM” port (I don’t pretend to know what that is, but it’s there).

Although there is much more experimentation I could do to identify all possible combination outcomes (if time were unlimited), so far I’ve consistently established that if the Midihubs are powered on last, then the DAW’s dropdown list to setup MIDI control sources and destinations for instruments shows them each with their unique serial numbers and four ports (depending on the direction, either to or from) each, and I am able to route MIDI signals through the identified Midihub ports and through the DAW from any source to any destination.

If, however, the Midihubs (even if just two) are on before the DAW, or before booting the PC, then all 16 (or 8, or 12, depending on the number of units active) entries in the dropdown pick lists show only one, repeated, serial number from one of the active units, and aside from then not knowing which is which, even if I try all of them, none will work, i.e. the same MIDI stream that was running in the prior scenario doesn’t seem to pass through any of the selected port choices.

Because these routings in instrument setups need to persist from one session to the next, it’s important for the same units to be recognized consistently. I would hope this is possible without needing to follow a strict power sequencing scheme, for a few reasons: just because, for convenience and flexibility; also because one of my Midihubs is in the back of a rack, and isn’t immediately accessible, and I’d like it to be left on locally, the power being switched on a power strip; and because frequently my DAW hangs when these devices are powered up or down, thus requiring a forced shutdown and restart of the program, after which there’s a chance the same thing will happen repeatedly.

FWIW, another, similar, device, of which I have two, without unique identifying numbers, will not consistently match hardware to the DAW’s identification, so sometimes 1 is 1 and 2 is 2, other times 1 is 2 and 2 is 1, but at least if I attempt to route with taking that into account, it will function. Oddly, the way I’ve had to get those to consistently show up correctly is to turn them on after the PC, but before starting the DAW, so not quite the same workaround. Those units have a power supply, if that makes any difference.

Any help, advice, and fixes appreciated.

Hey, this is unfortunately an issue with Windows OS itself - occasionally it fails to enumerate the devices, especially when they’re the same kind of device (same USB Vendor Id and Product Id pair), even though each device reports a unique USB Serial number. The OS seems to do some caching to cut some corners which ends up just to confuse itself…

My main OS for development is Windows, and I did encounter the same issue myself occasionally, but I didn’t ever see this happen on Linux or macOS.

I have an idea that we could try out, I’ll send you a couple of custom firmware builds next week to try out and see if it helps Midihubs to be always enumerated consistently on your setup. :slight_smile:

1 Like

Thank you. Others have also mentioned that Macs handle these things better. Oh well. I’ll be on the lookout for any updates you send.

Check your inbox :slight_smile:

1 Like

OK, I followed the instructions you sent, and I have just one question: are you a genius? It all works now, totally organized in the selection lists in the DAW, I’ve tested 3 units (again, the 4th is buried in a rack) and routed my keyboard into DIN inputs, and looked for the appropriate USB port in the software, and it’s working great on all three. Restarted Studio One while leaving Midihubs on, still works. Rebooted computer, leaving Midihub on still, and same result. This is awesome, thanks a million!


Hey! I am having a similar problem. Two Midihubs and Windows 10 softwares (MidiOx, Circular Labs Mobius, Reaper) all seeing both Midihubs enumerated as the same serial, though obviously Midihub Editor sees two different serial numbers.

I am encouraged that you were able to fix Hans303’s issue, is it possible to do same for the two (and soon to be a third) Midhubs that I have? Would certainly appreciate it!

1 Like

We determined that even though Midihub provides unique USB Serial numbers when getting enumerated, for some reason Windows OS ignores that, and usually differentiates devices just based on the USB VendorId and ProductId pair, which is obviously the same value for every Midihub.

The workaround was just to flash different firmwares to each Midihub, with a slightly changed ProductId pair, then each of them get properly enumerated.

We’ll consider adding a new setting to manually override the VID or PID value, so this issue on Windows can be worked around. In the mean time, I’ll send you custom firmware files to flash on each different Midihub unit. :slight_smile: If anyone else would like to have it, let me know. :slight_smile:

Very painless, worked great, thank you!

1 Like