These "professional" reviewers...how about reviewing Vita games on their own merits, except continuously drawing comparisons to consoles and using them as the measuring stick for a handheld? If you can't actually describe them and need to resort to similes or tired metaphors, I'm sorry but you're not that good at critical writing- try writing short stories or something.
The way to fix the problem is to change the setting. Instead of left+right you need to set it to either left or right only. This happens to me during movie playback, not music. Not sure about custom music during gameplay.
Someone just pointed this out on the Vita subreddit on Reddit - the music tracks are WAY off balance. Try going in game and putting the music on, then cover the left speaker. Then cover the right speaker.
The way to fix the problem is to change the setting. Instead of left+right you need to set it to either left or right only. This happens to me during movie playback, not music. Not sure about custom music during gameplay.