MTP/AV USB Problems When Connected To USB Hub

misterhemi · Post by **misterhemi** » Tue May 06, 2008 10:08 am

*sigh* *sigh* *sigh*

I was hoping to be able to connect everything without always having to switch cables.....

Here is the situation:

I have 2 MTP/AV USB's in 2 racks. In each rack along with the MTPs there are other USB devices.

In one rack there is an MTP and an Akai Z4.

In the other rack there is an MTP and a Korg Radias.

I need a hub in each rack in order to connect all of the USB devices to my Mac Book Pro, however, when I use the hubs Audio MIDI Setup and DP don't see the MTPs.

In the system profiles ALL devices are shown. I have had this problem with other hubs (USB 2.0) I had. I bought new hubs (USB 2.0) yesterday in an attempt to resolve the problem as USB 2.0 is suppose to be backwards compatible with USB 1.1 devices

Now, in one of the racks a few days ago as a test I used an older hub (probably a USB 1.1 device) that was laying around and the MTP and Radias were both recognized by DP and Audio MIDI Setup.

Is there some quirk with using USB 1.1 devices (MTP/AV USB) through USB 2.0 hubs???

As I said previously all of the devices (the 2 MTPs, the Akai and the Radias) are seen by the System Profiler.

This is rather annoying as it is seriously hindering my music projects

I could go back to switching cables but I do a lot of sound design and need to be able to create sounds on the Radias and export samples (via Akai Sys) to the Z4.

Any ideas? Any suggestions?

Don T · Post by **Don T** » Tue May 06, 2008 4:50 pm

Hello,
All I can say is "not all hubs are created equal." We had D-link hubs here that would constantly drop or not recognize devices. I replaced them with some cheapo brand from Fry's and all is well. After going around with D-link I got no straight answers except that it was my fault, bad cables or Mac. Then again my G3 used to drop the mouse or keyboard when I had a USB MIDI interface running, and that's with no hub.

The D-link recognizes the gear if I remove & re-insert the cables hot swap style. This was a pain in the @#$ cuz' I had to dive under the workstation to do the deed.

Do you notice that the USB list populated by the sys profiler is never in the same order?

Good luck

misterhemi · Post by **misterhemi** » Tue May 06, 2008 9:46 pm

Interesting. I hadn't noticed the order of items on the list.

I am hoping to eventually find some hubs that work.

Right now I have things working but not as I would like. I have 2 16 space shock-mounted racks and climbing behind them is like climbing under the desk you mentioned.

I'll explain what I did.....

I have one rack that we'll call "Rack-M" for modules and another we'll call "Rack-K" for keyboards. These racks contain the MTP/AVs, each has a Rolls RM203x mixer, effects, etc...

Rack-M is full so I have one module (the Korg Radias) in Rack-K.

The Akai Z4 and the Radias both have USB ports, so I took a cable from the Z4 (in Rack-M) and connected it to the USB hub I have in Rack-K and that is not connected to the sole USB port on the right side of my Mac Book Pro. The MTP/AVs are connected, individually, to the 2 USB ports on the left side.

My hope was to have the MTP in Rack-M paired with the Z4 on a hub in Rack-M and to have the MTP paired with Radias on hub in Rack-K so then I would have only 2 cables and not have to run a cable between the 2 racks.

Anyway, Thanks for the reply!

I am wondering in the "cheap" hubs you mentioned are USB 1.1 hubs as I am thinking there is perhaps some oddity that is happening when the MTP (which conforms to USB 1.1 standards) is connected to USB 2.0 hubs.

Later I may buy some cheap hubs (if I can find them now) or order two over the internet that I know are USB 1.1 hubs. I am willing to bet that will resolve the problem.

I want things to be rock solid as I plan to use this configuration for live shows.