USB and audio/midi - various questions!

bigblip

New member
Hi,

I've read that you shouldn't connect audio related equipment through a USB hub, but rather go directly to the computers USB ports. I've read this for audio interfaces, midi control surfaces and keyboards and external drives containing samples.

So, here are my questions. (Sorry, on re-reading this before posting I realise I have gone a bit overboard with the number of questions!):

1. Why? I am guessing that it's to do with overloading the single connection from the hub to the on-board USB but I haven't found a simple clear 'this is why you shouldn't do it' yet. Further, does the 'don't do it' statement refer to all types of hub, or just passive ones? Is a PCI Express USB card considered a hub?

2. Given that midi data is relatively small, compared with audio, what's the reasoning behind saying you shouldn't connect USB midi gear through a hub? Given the choice (which I have on a couple of my midi devices) should I use the native midi connections in preference to USB?

3. I run a small media production business and I create, work with and archive a vast amount of video and audio data. I have ten external hard drives (a mixture of USB 2 and 3) and until now they have been connected fairly randomly to direct USB ports or through a couple of powered hubs. I really would like to consolidate these, ideally to a single powered hub. Typically, I don't access these drives frequently, other than to archive the day's work, or a finished project. That's with the exception of things like stock music, sound effects, stock images, specific client templates/assets etc. These are all stored on one of the external drives. I also have a separate external drive for my twenty years-worth of collected samples. Is the strategy of hanging all ten drives off a single powered hub risky? Am I introducing problems elsewhere? Should I disconnect drives until I actually need to use them?

I'd welcome any advice.

My audio interface (temporarily a Focusrite Scarlett 2i4 following the death of my 6i6 :( ) is on a dedicated USB port on the PC. I also have a PCI Express USB 3.0 card which has further ports, to which I connect 2 x midi keyboards, a Korg nanoKONTROL Studio, an AKAI LPD8 and a Korg padKONTROL. My PC is quite well specced (i7 980 at 3.33GHz, 24GB ram, Win 10).

Thanks :-)
 
The use of the hub introduces some delay because it is actually a piece of firmware and storage that is doing packet routing. For archival/storage tasks, or devices with low data rates, like keyboards, mice, i.e., nothing with a "real-time" demand, they're fine. It's just when you are trying to record with minimal latency (e.g.) that having your interface or project storage connected off a hub that things can get problematic.

Unless you've got a background A/V app or Windows search indexer scanning those external drives , they're not going to cause any problems being connected via a hub.

And, of course, if everything's working, no need to go start moving things around!
 
Thanks Keith,

The interface is directly connected to the PC and active project content is all stored on internal drives. Having said that there have been occasions where I have referenced (for example) a set of client branded graphics that sit on one of the external drives (rather than having multiple copies). So far I don't believe it has caused me performance issues, although perhaps I should look at copying them to the active project disk.

Very good point about background A/V and indexing. I think I am guilty of both. I'll look at my A/V and see how to stop it scanning the external drives (it does a full scan every night anyway and the drives contain almost 100% media only). I'll also see how to turn off indexing for those drives.

if everything's working, no need to go start moving things around!

Agreed! However, I really do need to straighten things out! I have USB cables at the front, the rear and the top of my tower, as well as one hub hanging off the back and another hanging off the front. It's a mess! I'd like to be able to line up all the drives together on a single shelf :-)

Thanks again for the feedback.
 
This raises a further question (sorry!) . . .

One of the external drives is shared across the LAN so a separate editing system can access it. Is that a foolish thing to do?
 
FWIW, once I settled on my setup and how I wanted to set up my space, I bought correct length cables. Amazing how not having a couple feet of cables wrapped up adds so much space and neatness. A few 6" and 1' usb cables helped me out a lot, using one end right angled helped here and there too.

M
 
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