I'll try to explain this as simply as I can. Sometimes when I play YouTube videos, click on videos inside of Facebook, videos from other websites, the volume is slow low I can barely hear it. I have very powerful speakers (with a sub-woofer). I know that it's Firefox, because if I switch to Chrome and play the same video, I'm rocking the walls! Before anybody says anything about Facebook, please don't tell me to contact them. There is no tech-support for Facebook, and this phenomenon happens across lots of platforms, including Facebook. Also, with Firefox only (and Internet Explorer is unusable with my configuration, so that's out!), if I have a Facebook tab open, another tab playing a YouTube video, Firefox audio goes really low on the video to play the sounds coming from Facebook. There is no other platform to compare this nuance with except Facebook & other websites that have audio sound-clips, videos, etc. There is a sound-clip in my chat window that won't sound-off at all, but when I use Chrome on the same sound-clip, I can hear it fully! If I create my own sound-clip, using my cellphone, I can hear it in the chat window with Firefox Quantum. The sound-clip that won't play at all came from someone else into my inbox. So, it would appear there are a couple of problems here, and I have no idea why Firefox Quantum is behaving this way. I will not provide screen-prints of my Facebook account in here at all; that would be a privacy issue for me. So, anybody who responds, please understand this and trust that these are consistent problems ... not intermittent. Thanks.