The audio from a video continues to play when the slide is changed. So if there are multiple videos in the slider audio from each of them can play simultaneously. Can the slider be set so audio stops when the slide is changed or so audio from multiple slides won’t play at the same time?
Most likely you are using bx slider module. We will fix this issue in next version of slider plugin. I will inform you about the update.
In the meantime try to change slider module on jssor – http://prntscr.com/a1it2y
It should work fine with videos.
I’m using the jssor slider with a youtube video embedded. The problem I’m running into is that the thumbnail image of the video disappears after one round through. I noticed this is also happening on your example slider here: http://supsystic.com/plugins/slider/