I have a Lenovo Slim Pro 9i. I noticed an issue with audio quality on ubuntu when compared to windows but couldn't figure it out. Now after a week of use and leaving a video opened I figured out why. When I opened my laptop and hit play, the audio quality was louder and clearer than it has been before. But later when I started watching that same video, the audio was quieter. For some reason, after I stop playing a video and wait for a bit, 4 of the 6 speakers just stop working. They start working again after I power up the laptop again. I'm not sure why or how to fix it. I have tried using alsa but I really don't know what I'm doing.