My macbook pro has 2 USB ports and I was trying to get my V-Drums recognized in Logic Pro X to track the kit. Plugging in to the left side USB, wasn't seeing a signal. Plugging in to the right side it works. Same for a MIDI keyboard, right side only works. Yet, the left side USB works for an EXT HDD.
How would I setup the USB ports to allow (2) channels of MIDI inputs?
thanks
MacBook Pro with Retina display, OS X Mavericks (10.9.4), Logic Pro X; Final Cut Pro
This might be an example of the well known... 'lacking available power for certain USB2 devices and ports...' issue with USB3 ports......
Power down your Mac....(Important!.. Don't just put it to sleep)
Use a Powered USB2 hub plugged into the USB3 port that doesn't work.. Now plug your device(s) into the powered hub.....
Power up your Mac and test....
This might be an example of the well known... 'lacking available power for certain USB2 devices and ports...' issue with USB3 ports......
Power down your Mac....(Important!.. Don't just put it to sleep)
Use a Powered USB2 hub plugged into the USB3 port that doesn't work.. Now plug your device(s) into the powered hub.....
Power up your Mac and test....
But would this matter even if I only use (1) MIDI device? The issue is only evident with a single device only in the left USB port. I'm not following your reasoning for testing with a powered hub.
Some MBP's had a high power & low power port, they were designed this way, how old is the MBP?
bought mine March 2014
AOS's advice is good, try a powered hub.
SFSaxguy wrote:
But would this matter even if I only use (1) MIDI device? The issue is only evident with a single device only in the left USB port. I'm not following your reasoning for testing with a powered hub.
The reasoning is as follows...
1) Due to the way certain USB 2 devices were initially designed to take advantage of a higher power mode that USB 2 ports could provide...... Some bus powered USB2 devices need more 'power' at times than a single USB3 port can provide..
2) On some Macs.. (as Pancenter alluded to... and thanks for reminding me about this 🙂 ) the bus that is connected to a USB3 port... is being shared internally... with other components.. reducing it's total available 'power'... Ports on one side compared to the other, may have different levels of 'power' available on their bus... because the bus on one side.. may not be shared with something else.. or not with as many other things.
Theoretical Example: Bus 1 has 2 x USB 3 ports connected to it... Bus 2 has 1 external USB 3 port, 1 internal USB 3 port and 1 SATA port connected to it.. Bus 2 therefore has less total available 'power' available to a device connected to it.. Certain USB2 devices connected to Bus 2 may not function correctly because of this lack of available 'power'.. where as they will work when connected to Bus 1
3) Powered Hubs supplement the total available 'power' available via the bus/port
4) This workaround has been proven to work time and time again (though not always I might add) ...with certain USB2 audio / midi / external devices not functioning/ being recognized when connected to a USB 3 port 🙂
The Art Of Sound wrote:
SFSaxguy wrote:
But would this matter even if I only use (1) MIDI device? The issue is only evident with a single device only in the left USB port. I'm not following your reasoning for testing with a powered hub.
2) On some Macs.. (as Pancenter alluded to... and thanks for reminding me about this 🙂 ) the bus that is connected to a USB3 port... is being shared internally... with other components.. reducing it's total available 'power'... Ports on one side compared to the other, may have different levels of 'power' available on their bus... because the bus on one side.. may not be shared with something else.. or not with as many other things.
Yes, recent Laptop motherboards, both Mac and PC which are basically the same now, make heavy use of internal USB, even internal audio can be using the USB bus. (why, cheaper of course).
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of (2) USB ports, only one MIDI?
