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User profile for user: bigdave1357
bigdave1357 Author
User level: Level 1
35 points

El Capitan intermittent USB multi-media

I use a pair of Bowers & Wilkins MM-1 speakers which have worked flawlessly through several revisions of OSX.


Having just upgraded to El Capitan I now find that my Macbook Pro will often fail to recognise them. I have my speakers plugged into the USB port on a Thunderbolt display and I find that having disconnected my Macbook from the display and then returning later, it will not then detect the speakers.


A full OSX reboot solves the problem every time. If I boot with the Macbook either connected to or disconnected from the Thunderbolt and then hook everything up it will then happily find and work with the MM-1 without any issues. It seems the act of disconnecting from the Thunderbolt is causing the issue.


I've also noticed that video devices (such as the Thunderbolt camera) are also not being detected properly after a disconnect from the Thunderbolt, nor the in-built Thunderbolt audio either - all of which presumably hang off the internal USB bus.

Never seen this behaviour before and it is coincident with the El Capitan upgrade. The fault is very repeatable. A reboot always cures it. Same thing occurs if I use other Thunderbolt displays. Got to be an El Capitan bug surely?


Anyone else seeing anything similar, perhaps with other types of audio or multi-media kit?

MacBook Pro, OS X El Capitan (10.11), MM-1

Posted on Oct 5, 2015 9:58 AM

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33 replies
User profile for user: bigdave1357
bigdave1357 Author
User level: Level 1
35 points

Dec 20, 2015 2:04 PM in response to bigdave1357

That's also how the problem manifested itself to me. The Mac would "see" the MM-1 connected (if I looked in the Sound section of System Preferences I could see the speakers in the Output tab) but nothing would play through them - attempts to stream or play anything with audio through the MM-1 would simply cause the playing app to freeze. As soon as I selected internal audio everything work normally again.


The fix was either a reboot or "sudo killall VDCAssistant". This was on 10.11.0 but such problems had never occurred on Yosemite.


After the 10.11.1 patch the sudo workaround then failed to recover the situation and the only option was a reboot. Extremely frustrating - every time I disconnected from the Thunderbolt I then had to reboot if I wanted to use the MM-1.


Since 10.11.2 the problem seems to have vanished for me with MM-1 but there are others with different devices that are still having the problem. Throughout the whole thing I've not changed the MM-1 firmware nor has there been an update to the Thunderbolt firmware as far as I can tell.


Having done some further testing I can confirm that I still have a similar problem with the Thunderbolt and charging devices. After a clean reboot the Macbook works normally with regard to charging devices such as iPhone, iPad or Watch. However, once it has been connected and then, crucially, disconnected from a Thunderbolt, it will no longer charge anything properly. Once the Macbook goes to sleep any connected device will not be charged. The only way to fix it is, you guessed it, reboot the Macbook once more.


There are other threads that report similar problems charging. I'm certain that Thunderbolt connectivity is triggering these issues for me - certainly for the MM-1 although that has now gone away, but the charging problem remains.

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User profile for user: lupusyonderboy
lupusyonderboy
User level: Level 1
4 points

Jan 20, 2016 7:56 AM in response to bigdave1357

Updated to 10.11.3 this morning. Listened to music in iTunes all morning, everything was fine. Watched a Youtube video, and bam. Just like before.


process Google Chrome He[8211] caught causing excessive wakeups. EXC_RESOURCE supressed due to audio playback

USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-302 .15/AppleUSBAudioIsocPipe.cpp at line 106

USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-302 .15/AppleUSBAudioIsocPipe.cpp at line 106

USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-302 .15/AppleUSBAudioEngine.cpp with return 0xE00002BC at line 2181

USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-302 .15/AppleUSBAudioIsocPipe.cpp at line 152

USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-302 .15/AppleUSBAudioIsocPipe.cpp at line 106

USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-302 .15/AppleUSBAudioIsocPipe.cpp at line 106

USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-302 .15/AppleUSBAudioEngine.cpp with return 0xE00002BC at line 2181

USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-302 .15/AppleUSBAudioIsocPipe.cpp at line 152

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User profile for user: wluman
wluman
User level: Level 1
0 points

Feb 7, 2016 8:37 PM in response to bigdave1357

I've been having the same issue and sent my MM-1's back to B&W under the assumption that it was a hardware issue (as I hadn't seen this forum yet). They notified me that it was Apple's fault and sent me my speakers back. After the most recent update (10.11.3), my speakers worked perfectly until 10 minutes ago, when they went out again. This is the most frustrating thing, since I have an iMac 13,2 and the built-in speakers aren't that great, especially compared to the MM-1's. I hope Apple re-fixes this issue ASAP.

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User profile for user: bigdave1357
bigdave1357 Author
User level: Level 1
35 points

Feb 8, 2016 1:24 AM in response to bigdave1357

Looks like there are still plenty of USB related issues, even after the latest fix. My audio problem with the MM-1 has not come back when plugging into either the MacBook or a Thunderbolt so I must just happen to have a combination of hardware (MBP Late 2011) and Thunderbolt that doesn't trigger the problem. But my other issues - USB charging - still remain so there are definitely still issues.


ftoft has posed a useful workaround - hook up the MM-1 to your laptop using a 3.5mm jack. However, if you do this you will not get quite the same audio quality. If you're using the audio output of the laptop then you are relying on it's DAC to give you your sound. Connecting the MM-1 directly by USB means that it recieves digital audio and uses its own DAC which is much higher quality.


You might not be able to hear the difference, and it is a good compromise. The big problem here is how long this has been going on. There is so much in the other forums about ongoing USB connectivity and charging problems with El Capitan that go right back to the beta. Getting very, very old now, Apple.

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User profile for user: wluman
wluman
User level: Level 1
0 points

Feb 8, 2016 7:02 PM in response to bigdave1357

Thank you to both bigdave1357 and ftoft for the responses. I agree that I could use the included 3.5mm audio cable as a workaround for my MM-1s, but the restarting of my iMac has (thus far) fixed the problem. However, just as bigdave1357 has stated, the bigger problem is not my loss in audio quality but the ongoing USB issues with OS X. As the latter stated: "Getting very, very old now, Apple."

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User profile for user: Shoplifter
Shoplifter
User level: Level 1
0 points

Feb 16, 2016 1:20 PM in response to wluman

My guess is that these issues with the B&W MM-1 are related to the new USB power management system used in El Capitan.


Take a look at page 9 here: https://www.apple.com/osx/all-features/pdf/osx_elcapitan_core_technologies_overv iew.pdf


I did put in a ticket with Bowers and Wilkins and they basically told me to revert to an earlier version of OSX, which is not really possible at this point.


So at least as of now Bowers and Wilkins does not have a fix and these may or may not work. I have found that they are working a little more reliably with the 10.11.4 beta, and that if I never stop playback and always have iTunes playing softly in the background they do not cut out.

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User profile for user: bigdave1357
bigdave1357 Author
User level: Level 1
35 points

Feb 16, 2016 1:28 PM in response to Shoplifter

I think you are right - this is related to the USB power management "features" in El Capitan, and I'm certainly still seeing plenty of power related issues - mainly devices not charging properly unless I reboot my MacBook.


However, since 10.11.2 my MM-1 issue has gone away. But since others are still experiencing this I conclude that the original MM-1 issue in particular is related to both the USB power management as well as the particular hardware platform.


I have a MBP 17" Late 2011. Others with more recent hardware seem to be still suffering from both USB issues as well as the MM-1 issue.

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User profile for user: lupusyonderboy
lupusyonderboy
User level: Level 1
4 points

May 18, 2016 6:20 AM in response to wats67

Well, unsurprisingly the error still happens in 10.11.5. Tried USB again this morning, just using iTunes and it crapped out on me after an hour or so.


USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-303 .3.1/AppleUSBAudioEngine.cpp with return 0xE00002BC at line 2181

USB Sound assertion in /BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-303 .3.1/AppleUSBAudioIsocPipe.cpp at line 152


Starting to give up hopes of ever being able to use these speakers with this monitor.

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El Capitan intermittent USB multi-media

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