audio volume low when computer wakes from sleep - os x yosemite

Hi dab417,

Welcome to the Apple Support Communities!

The first troubleshooting step that I would suggest in this situation would be resetting your computer’s PRAM. Please use the steps outlined in the attached article to complete this process.

OS X Yosemite: Reset your computer’s PRAM

Have a great day,

Joe

Hello dab417,

Thank you for using the Apple Support Community. Due to the nature of your issue or question you may find more information by using another one of Apple's support resources - https://getsupport.apple.com/GetproductgroupList.action.

Cheers,

Joe

dab417, I am having the exact same problem. Speakers and keyboard volume controls work fine until Mac goes to sleep. When it wakes the speakers volume is low and cannot be raised or lowered by any means. After a restart, everything works again.....until it goes to sleep.

Computer: New Mac Pro (Late 2013)

System: OS X Yosemite 10.10.1

Speakers: Bose Companion II Series 2.

joe_7399: Resetting the PRAM did not solve the problem.

Is there any new information on this issue?

John

Sound Levels - Troubleshoot

Thanks for your help, Eric. I will try some of those suggestions.

Here's one I found that does work, at least temporarily until the next time the issue appears. A Terminal command -- sudo killall coreaudiod -- that restores audio function without necessitating a full system restart.

This is a BUG. It has been submitted to engineering many times - unfortunately Apple has not done anything about it. We have 5 Mac Pros, all 5 do the same thing after updating to Yosemite. The PRAM / SMC reset is useless - we even installed a fresh OS on one of the machines (a suggestion of the level 2 Apple tech) same problem. Clearly this is a system level bug. Only way to get it resolved is to keep pounding the bug report site with requests. The squeaky wheel gets the oil. The problem is 100% repeatable on the machines that exhibit the bug.

In the mean time set up an applescript with this command and it will reset the sound - do not include the brackets :

<do shell script "sudo killall coreaudiod" with administrator privileges>

Run it every time you wake from sleep and you won't have to deal with the problem ever again.

Pretty lame that Apple has not fixed it even though the problem appears to be pretty widespread.

Here is what seems to work for me: reset PRAM, reset SMC, repair permissions, and check correct settings in Audio MIDI Setup.

so far, so good!

Thanks for your help. I will submit a comment to Apple, as you suggest.

I followed the exact procedure that TheRealJG suggests above - and it fixed the issue - apparently repairing permissions AND opening / closing Audio MIDI somehow correct the problem. We applied this to all our machines and it so far has stuck - no more low audio on wake.

Interesting, but good investigative work TheRealJG ! Thanks !

In Macs as in golf, it's better to be lucky than good.