Conecting multiple midi devices via USB hubs.

[nihercop]

Hello!

I´ve been struggling trying to connect multiple devices (Maschine + Novation Impulse + External Hard Drive 1Tb + Avid Fast Track usb audio/midi interface) to my computer.
I bought an Usb 3.0 hub (poin order to be able to connect all the devices to my macbook pro and use them at the same time, as it only has two usb ports. However I obtain latency when using my Impulse controller and the midi interface.

Does anyone knows why does this happen?

Thanks in advance!

Cheers.

[SODDI]

Hello!

I´ve been struggling trying to connect multiple devices (Maschine + Novation Impulse + External Hard Drive 1Tb + Avid Fast Track usb audio/midi interface) to my computer.
I bought an Usb 3.0 hub (poin order to be able to connect all the devices to my macbook pro and use them at the same time, as it only has two usb ports. However I obtain latency when using my Impulse controller and the midi interface.

Does anyone knows why does this happen?

Thanks in advance!

Cheers.

Check with the manufacturers to see if all your devices are USB 3.0 capable. Some are not. (My Audiobox USB is not.) That could be the problem.

In addition, there seems to be some weird USB voodoo shit on my system and there might be on yours, where certain devices do not like to be on the same USB bus with other devices. I'm serious. Do the trial and error thing, group any MIDI over USB devices together, you know the drill. Good luck.

[Kumi_27]

You know, USB is a serial bus. It means, it serves one device after another.
In best case with balanced load Your 4 devices will have 4 times slower access than plugged directly.

I'd start my tests with disconnecting the drive. Maybe it's hogging the transfer.

[GaryG]

I'd definitely try giving the audio IF it's own socket then chaining everything else through the hub.

This is what I ended up doing, never had a problem with multiple midi usb devices on a hub.

[whyterabbyt]

You know, USB is a serial bus. It means, it serves one device after another.

Thats not strictly true. A serial bus only means it sends data packets one after another. The order in which devices are served is not quite so simple, as those packets can be interleaved. Plus USB has three data transfer types, one of which prioritises a guaranteed bandwidth (eg for video cameras) another of which prioritises response time (eg for mice) and the last of which is 'sporadic' aimed at bulk transfers between other prioritised requests.

In best case with balanced load Your 4 devices will have 4 times slower access than plugged directly.

Not necessarily true. It depends very much on what the devices are eg if its three mice and a USB drive, the USB drive transfer rate will hardly be affected. If its an audio interface and a USB drive, the audio interface should be getting priority.

Best way to diagnose what's happening is probably to swap stuff around and try and determine exactly what combinations cause it. Personally, I wonder if its more likely to be the fact that there's USB3 hub. If the OP could borrow a USB2 one for comparison, that would be useful.

[Kumi_27]

You know, I could put a longer technical explanation too but for practical purposes, it still means that USB can transfer data from one device at any given time
And it still means, that the transfer from one device will be more or less affected by the other ones.
Here we have two devices that might request large amounts of data - drive and audio.
And we don't know, how the priorities are handled in this case.

[jabe]

I've never got on with USB hubs. They always seemed flakey. I had maybe three USB drives and external HDDs attached, and they didn't seem to work as they should. If your PC is a desktop, I'd see about getting one or more PCIe (or whatever it is these days) USB3 cards and sticking them in.

If your devices are sending MIDI in and out, the amounts of data involved will be tiny and shouldn't be causing problems.

[Kumi_27]

If your PC is a desktop

You know, it's a macbook pro... it's not exactly a desktop

[jabe]

If your PC is a desktop

You know, it's a macbook pro... it's not exactly a desktop

Sorry, I missed that bit. Always had that problem with exams at school. I once changed a hard drive in a MacBook for someone. Horrible.

[thecontrolcentre]

Have you tried plugging the audio interface into a USB port and everything else into the hub? Is the port you have the hub connected to definitely a USB3 port? The problem may be that your devices are USB2 ...

That said I have 3 midi devices connected to a USB3 hub. Novation ReMote SL, PUSH and a Microbrute. All are USB2 compliant. No latency problems. My NI Audio Kontrol 1 is connected direct to a USB2 port, altho it also worked fine attached to the hub.

Maybe try a USB2 hub instead?