So either I'm going crazy and it's been humming all along, or it just started to him full time this evening.

I'm second guessing myself now, but earlier today I must have tried powering it on and off at least 5 times and I was confident the humming was gone when powered back on and I also tried adjusting the sub volume once and turning the knob made no difference.

Just now I checked it and it's basically humming at all times. I turned the volume up and the humming gets worse, when my volume is up past 50% it starts to make a rumbling sound accompanied by a static/white noise type of sound. A sound similar to being tuned into a radio station that you aren't receiving the signal for. When the volume is below 50% the white noise sound goes away and it's not a rumbling sound, just a steady hum.

What do you make of this?