Wait you miss the point of my simple test.
Question 1: What is a wakelock?
XDA Wiki: Wakelocks statistics are good indicators if the battery drain is high when the phone is off and supposed to sleep.
But... but ...but your device screen was not off nor was it suppose to sleep as you are watching youtube.
Conclusion:
Since android 4.1.2 please just
IGNORE audioout_2 wakelock reported in BBS because its
NOT AN ACTUAL WAKELOCK.
Anything with media sound eg video watching, playing games, youtube, mp3 listening will contribute to audioout_2. Unless you tell me you watch video or play games with the screen off then i will admit something else is wrong.
Just enjoy your device...
Will do. After so long only realize it was youtube... LOL