I wasn't able to find it just now, but I remember a warning several years ago in a SuperCollider tutorial to the effect of "Mac OS X does not hard-limit maximum

I wasn't able to find it just now, but I remember a warning several years ago in a SuperCollider tutorial to the effect of "Mac OS X does not hard-limit maximum volume, so BE VERY CAREFUL! You can damage your ears and hardware!" I'm sorry you lost internal speakers to that.