I have a macbook pro late 2011 and about a year ago updated OS X to 10.8.5. I downloaded purchased Boom to enhance volume and have had a problem with the sound ever since - tinny and difficult to understand. I properly uninstalled Boom from script, but still sound issue, which may have been a coincidence with downloading Boom. I really need to repair the sound. Will downloading Yosemite fix the sound problem? iow, will it undo, rewrite or whatever, any drivers or whatever may be causing the problem? If so, are there any other problems with Yosemite I should know? iow will it retain my list in my itunes library as is, iphoto events organizing etc etc.? If not, how might I fix this sound problem. I feel like I've tried everything short of reinstalling OS X completely.