Loss of volume in 10.1


I have found that after running 10.1 and iTunes and many ( up to 20 ) other programs, that at some point, the max volume drops by a very noticeable amount.
Someone else had posted about a lack of bass in 10.1, after running for a certain amount of time. I have not figured out any correlation, but it does happen at some point and restarting always fixes it. Logging out and back in does not. This has only been noticed on the Mac shown in my sig. I have it running on two other Mac but I don't run as many apps on them or use as extensively.