Hello, I don't have any idea of how to solve this in an effective way. But, it could be due to many factors, like the headphones (as you've posted), your PC configuration or the particular browser. From my experience, I can say the audio in Opera sounds lower and I have to increase the volume of my PC to almost 100. However, when I use my headphones (it's mark is Tritton), the audio it's better and I'm able to decrease it to 30. I think this is primarly because of my PC, but it's true that in Chrome the audio seems to be in a better quality (just a bit, though). I'd recommend you to configure the sound configuration of your PC, and try various options and variables.