I posted this last night in another forum
"I used disk utility to repair the permissions nd all that crap, restarted a few times. someone in another forum suggest resetting pram but then someone else said it didn't work either. the problem remains but i cant tell if its my cautious optimism thinking things are slightly better (after using the Utility)or..... maybe not. I'm also going easy on the system.
dont even try to play video games - enormous lag."
i havent reset the pram yet. the problem seemed ok but now its back.
i also am noticing something else. part of why i used safari is it seemed like - and I'm no computer person - google chrome built up cache in the background sooner than safari at one point, which I thought might be why it seemed faster. now I know this because I downloaded this application called "CleanApp" which tells me the amount of cache and choice to delete it. this is how i know this comparison. since yosemite the cache overall has been much larger and builds up quicker having to throw it away more often. which is strange.
i also get a sort of ghost image of the vlc viewer window after i've closed the program which disappears at about the same time as the audio delay is.
every once in awhile throughout the system the fonts will be a sort of pixelized rainbow color as well. there used to be muticolor squares in the place of icons the system had not loaded, or something, yet but that problem seems to have worked itself out. the audio still delays.
i have a late 2012 iMac etc..