(How To) Disable Mac Startup Chime

[Glenn]

I was hunting about for a fool proof way to disable the Mac Chime on Macbooks and iMacs, I think I found it:

Boot into Linux (Live or installed) to Remove the kernel-applied protection on the variable:

sudo chattr -i /sys/firmware/efi/efivars/SystemAudioVolume-7c436110-ab2a-4bbb-a880-fe41995c9f82

sudo rm /sys/firmware/efi/efivars/SystemAudioVolume-7c436110-ab2a-4bbb-a880-fe41995c9f82

printf "\x07\x00\x00\x00\x00" > ~/SystemAudioVolume-7c436110-ab2a-4bbb-a880-fe41995c9f82

sudo cp ~/SystemAudioVolume-7c436110-ab2a-4bbb-a880-fe41995c9f82 /sys/firmware/efi/efivars

Deleting and then creating and copying the var back to /sys/efi/efivars was the ONLY method that worked. Attempting to write the variable directly would give me a permission denied error, even with sudo and with its' immutable flag having been removed with chattr -i.

source: https://apple.stackexchange.com/que...disable-startup-chime-on-macbook-pro-5-2-2009


I can't say for sure it'll work for every mac, but as 99.9% of the google results are about adjusting this, I'd think it wont hurt to try

If you still have a mac OS installed or can get to the recovery OS (Command R) then you can simply press the mute button before you shut it down and it'll not have the startup chime anymore, you are able to adjust the volume as much as you want in Linux or Windows and it doesn't get saved to EFI variables.

 

[vanTorX]

Too complicated with the command line method, much better is the one when you boot into mac os and mute it before shutdown. I suppose it only holds for subsequent bootings into linux or windows, for mac os you would need to remember muting before every shutdown.

Imagine whole floor of open office cubicles in the morning when people would start their macs , fortunately in such settings, windows would be the choice. Don't know about newer macs but the old ones ~2007-12 are loud but my 2015 iMac has the chime reduced to a fairly decent volume that it almost doesn't bother you.

 

[pacav69]

if i was about to deploying a number of macs from the IT workshop i would either disconnect the speaker, or solder a resistor or potentimeter in line with the speaker to reduce the volume (mac users like a little noise) or find a software patch to disable the onboard speaker.