You said this happens on any outputs? Any amplification, home, car, whatever?

Okay, question. What do your EQ settings look like?

If it's all flat, then you might be looking at a hardware issue, like a bad component on the board, or something wrong with the DSP. I mean, setting the loudness too high will normally clip the outputs when combined with maximum volume and a bassy song. But at the volume settings you're talking about, it shouldn't happen I don't think.