I like loud (90+db) but usually I listen more in the 70-80db (peak) volumes. It’s more comfortable over time. My system isn’t fatiguing at all. I am just bombarded by loud all the time. A little more mellow is good. And I totally disagree with “play at concert levels” thing... that will kill your ears faster than anything. I’m a professional drummer, so I am VERY familiar with loud. I always wear ear protection at concerts these days. We are only getting older and I like hearing with detail.
