Hey all. I have a 5.1 setup using a Marantz SR7200 receiver, and some awesome PSB speakers. However, I'm having one small issue - whenever I use PCM audio over a digital optical audio cable, the bass is always cranked up way too high, and I can't understand why. However when the receiver gets a 5.1 signal, the audio is perfectly normal, and everything sounds great. The only time that PCM stereo comes into effect for me is when I'm using a 5.1 capable device (like an Apple TV, Xbox 360, my smart TV), but playing stereo only audio from that device. I have tried plugging my devices directly into the receiver using an optical cable, and I have also tried plugging the device into my TV through HDMI, and my TV into the receiver using an optical cable, with the same heavy bass occurring with each setup. Also, for some reason it defaults to PCM stereo instead of just regular stereo (is there a difference?), which I'm assuming is what's causing the bass issue, although I'm fairly new to all of this so I'm also assuming you guys know better than I do. Any ideas? Thank you in advance!