Sound and balance issues


macrumors regular
Original poster
Aug 25, 2011
Hi all

After upgrading to ML, I've encountered a bug where the sound after a bootup is extremely loud and only plays on the left side. This is very very annoying as I use headphones and my left ear does not like this.

When I go into the Sound page of System Preferences I can see the balance is indeed almost completely to the left. So I adjust it and it's all good again.
But as I don't want any eardamage and often forget to check it (I shouldn't check it in the first place), is this a known bug or is there anything I can do about it? Never had this with Lion.



macrumors regular
Jul 20, 2012
The balance changed for me to the left once. I thought I pressed accidentally some sort of hotkey that changes this.


macrumors newbie
Jun 6, 2012
I have a similar problem. Sound will shift to the left for no good reason.

Strangely, the work around requires that I go to the Output tab on the Sound prefpane. While there if I minutely adjust the 'Balance' slider back and forth the sound will completely disappear and reappear randomly in the right channel. Sometimes, if it's stubborn, I have to leave it full on to the right side and then adjust volume up and down until the right channel pops back in.

Once that happens the sound will be set (for awhile at least).

Anybody know what the heck is going on?


macrumors newbie
Apr 21, 2011
I got the same issue...

And also black/dark backrounds is small light dots are flashing... maybe just as big as one pixel...


macrumors newbie
Oct 23, 2011
Same on Lion

I can confirm that this issue started happening for me within the last couple weeks on Lion, which I've run for over a year. This seems to have cropped up recently as it never happened before and now seems to happen every time I plug in my headphones (maybe it happens without headphones too, but that would not be as obvious). Might have something to do with external monitor as well (mid-2010 MBP, 27" LED display).

Recent system update (10.7.5) issue?


macrumors newbie
Feb 22, 2014
same on Maverick

I am having the same issue on Maverick. After a couple of days the balance in my sound preferences will have gone completely to one side (in my case: the right).
This should not happen.