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i recently noticed the same on my tab s6 too after doing a security update. Thought it was just in my head so i played the same songs on both my tab s6 and alienware m15r3 laptop and the tab just sounds bland (i did the same thing when i first got the tab s6 and it was leagues ahead of the alienware in audio quality). My pen does not connect to the tab anymore either and the general performance of the device has been choppy after the update
