I’m an actual real live sound engineer. I’ve worked on low and no budget indie films. I’m mostly a band/live event guy but like I said…low budget. The only thing I can think of that would make sound this bad, even if you simply turned off 5.1 and randomly panned everything…is compressor/limiter artifacts. Like when there’s too much sound beeing pumped through individual channels to be combined so that putting them through the same channel causes the compressor to overwork. Or when you use panning as a replacement for actual mixing. AKA: bad mixing. Hence my rant.