Q: iMac late 2013 + Mavericks + USB Sennheiser - input freeze

For those still wrestling with USB bus freezes with iMac Late 2013 with Fusion drive and Mavericks, and who don't want to have to wait till OSX 10.9.2, I have found the utlity posted at this link way back on October 25th solves the problem:

http://www.enttec.com/support-center/kb/article/108-OS_X_Mavericks_(10.9)_-_IMPO RTANT

Not sure why this link has not been posted on this thread before!

As you will note from the associated page the author claims that Apple wrote their own USB driver in Mavericks and it has issues. The utility disables it, and reverts to a standard driver.

I have been running for 48 hours with this driver fix installed with zero issues. Previously with a USB hub connected to my iMac I would get an hour or so at best before a USB freeze.

As other have reported the issue is the USB bus.  The CPU itself does not crash; the iMac is still accessible via screenshare or fileshare while the bus is frozen, but it does take a restart to clear the USB bus freeze.

Hope this helps relieve some frustration while we all wait for OSX 10.9.2.

Wow, this is important information Peter,

Thanks for sharing.

I can't believe we are all in communication with Apple and they stay totally silent about this. They must certainly be aware of it.

Anyway, I'll give that a try. Thanks again.

This is what i find the most annoying!

I could deal with a "we are aware of this issue and are working on it", but the "you are the first person to report this problem, we never heard of it before you" they keep giving everybody is just very annoying and a compete lack of respect.

This is not a way to deal with an issue, and is bad PR.

100% agreement! As I talked to the support people I was pretty sure that they know the problem but they never admit it. I think they're afraid of too much returns of newly bought macs...

Hi Peter,

I tried your referred fix from Entec.

Seems to have worked no problem, and I have yet to see it freeze again, so I assume the fix was successful.

However now in Logic Pro X my audio tracks, with my Blue Yeti Pro Usb microphone as input, don't have a record button in the track. It looks like it sees the microphone, that it has audio enabled, etc, but I can't set it to record!!

Any idea if it good be related. I used to have no such issue. I could previously record although I would get a bad background noise and the freeze problem after a while.

I tried outside Logic Pro X with a simple recorder and it had no problem seeing and using my microphone.

Any idea?

Why would Logic Pro X suddenly disable recording on that device?

I tried creating new tracks, even new projects, with same results.

Cheers

Eric

Glad to see this Entec fix is helping, if only in part. 

Interestingly I have seen an occasional artifact on the audio side on my iMac as well, in that my external USB speakers disconnect not often but occasionally, but can easily be re-enabled in the Sound Preferences panel. I am guessing this may be related to the other issues, although hard to tell!

So I suspect that while the fix solves the USB crash (in my mind the most important concern) it still is not a full solution to all the USB audio issues that have been reported. Hopefully the driver update in OSX 10.9.2 will address ALL these issues.

Any idea how to revert the change to the driver though?

Reason I'm asking is I suspect that simply installing 10.9.2 won't be good enough anymore. I probably have to revert this "workaround" before proceeding with 10.9.2 when it's available.

Thanks

Eric

I suspect that if running the OSX 10.9.2 update does not overwrite the change, then doing a new combo install of OSX 10.9 will—keep in mind running the 10.9 install apparently changed the dirver in the first place!

Obviously you should address the questions on this topic to the original author of the fix if you have any issues.

Guys, I have to admit that I don't completely understand a lot of this discussion.  I'm just wondering, how certain are people that this is a software and not a hardware issue?  If there is a non-negligible possibility that this is a hardware issue, we're still within our 30 day window and could return this iMac and wait for a model that doesn't have this problem. 

It would be nice to be able to get this answer from Apple but they're playing dumb...which is really disappointing because we had higher expectations of Apple...

Thank you.

This is exactly why i have sent mine back, and will be waiting untill i know the problem is fixed to order again.

You obviously missed part of the discussion.

It was said that people running Mountain Lion on the same hardware didn't have that issue.

As well, running Mavericks from an external drive, on the same hardware, didn't show the issue.

It was even said that running the beta release 10.9.2 was fixing the issue.

All that proves that it's a software problem, not hardware.

I've started my iMac through target disc mode using my MacBook Pro and it works perfectly.  So that also shows that it is not a hardware issue. 

Carlos840: Thanks.  It's nice to know that I'm not the only one confused by all of this.

Elaurin03 and Fleabass: Thanks for connecting the dots for us.

Well Software on a particular hardware set up.

I ran with my Thumb drive as the boot Disc and had no issues, unfortunately doing this broke half a dozen minor things .

I reformatted and did a clean install of   mavericks split the fusion Drive using the SSDD as the boot drive and had the problem as well contrary to other reports.  But all the other minor issues caused by using the thumb drive where resolved

I reformated the split drives back to a fusion drive, did a fresh install again and used the USB driver mentioned above and 24 hours later have not yet had a problem.

Hi Paul,

That's great (although it's too bad you had to go through 2 reformattings).

And are you a Logic Pro X user?

I did the Entec USB driver change, and I have an issue where logic pro X won't let me record with my USB microphone (which I verified is working in other little apps).

So I'm just trying to find someone with the Entec driver who has that working in Logic Pro.

Cheers