Kara-Moon Forum

Developers & Technology => DAW => Topic started by: Moon on August 29, 2011, 07:08:38 AM



Title: Using USB hubs
Post by: Moon on August 29, 2011, 07:08:38 AM
While laptops are powerfull enough for running a DAW, they do have one shortcomming: limited USB ports.

One way to solve this is making use of a USB-hub. Simple connect it to one USB port in the laptop and you'l have an extra number of USB ports.

However: be carefull.

While tetsting this setup, I connected the following devices to the hub:
- keyboard (azerty in my case)
- mouse (trackball)
- soundcard (Alesis IO)
- touchscreen
- midi-keyboard (Nocturne)

All seemed to work fine untill I started having problems with hanging notes: apparently I started to miss notes-off messages from the midi-keyboard.

Connecting the midi keyboard directly in the laptop resolved the problem.

Conclusion in my setup: USB hubs are a solution but be sure you test the setup in order to determine how to divide the devices between the hub and direct connections in the laptop.

Moon


Title: Re: Using USB hubs
Post by: Marc JX8P on August 29, 2011, 09:14:03 AM
Very good point. My Macbook Pro which I use for live performances only has two USB ports (really, Apple?!? Why?!?) so this makes it necessary for me. I have my audio interface on one of them as I absolutely didn't want to run any risk of having it share the same bus with other USB devices. The other port has a LINDY usb hub on it. I had heard good things about LINDY's hubs and cables and have to say that so far it all runs great for me. The hub does all my controller keyboards (Novation 61 MkII, M-Audio Axiom 61 and the Korg M3 (last one does of cause do more than just control the laptop).

I'm also still working of integrating my iPad into the setup. While wireless would seem cool, in practice I anticipate connectivity problems and there's also the issue of charging the iPad over longer periods (though it does run very long on a battery charge). I'm therefore thinking of getting the iRig MIDI interface and connect it to one of the keyboards additional MIDI-INs. I've found a great piece of software for the iPad that basically allows you to design any kind of controller interface which also features feedback (it's called MIDI-TOUCH) and I plan to use that to get more feedback from my Live session (don't want to look at the laptop constantly). There's also loads of cool synthesizer stuff for the iPad that uses the touch screen and which sounds and plays differently than anything in my current setup (Jordan Rudess' Samplewiz is stunning).


Title: Re: Using USB hubs
Post by: bvdp on August 29, 2011, 04:12:56 PM
One thing to consider is power. Powered hubs make up for the lack of enough power from the host ... without an external PS to the hub you might be running into problems.


Title: Re: Using USB hubs
Post by: Oren on August 29, 2011, 04:34:01 PM
...Very good point. My Macbook Pro which I use for live performances only has two USB ports (really, Apple?!? Why?!?) so this makes it necessary for me. I have my audio interface on one of them as I absolutely didn't want to run any risk of having it share the same bus...
Good to know! Thank you, gentlemen. O0


Title: Re: Using USB hubs
Post by: folderol on August 29, 2011, 11:14:43 PM
I tend to think of USB hubs in the same way as mains power strips. Over here, a wall socket is rated at a current of 13A. You can plug in a 4 way strip and every one of the sockets on it is also rated at 13A. However, the plug in the wall is still only rated at 13A, so you can have maybe 6+3+3+1 or 9+4 but certainly not 5+5+5+5!

With USB the link between the hub and the computer has a finite data 'current', so using several sockets, like the wall plugs, will result in each one having less that the maximum.