Been listening to TH900 for a bit, another biodynamic, and yeah it's fun for certain genres and surprisingly open sounding for a closed back. But wow, coming back to Atrium you realize how well tuned the Atrium is. It just sounds so rich. It's been said many times before but every note feel like they have a weight behind them. Now I really want another closed back and I've been going back and forth between VC and AC for a while. Hopefully I get to demo them both one day and I can make a better decision of what I want, but one thing's for sure: Atrium Open will stay in my collection for a very long time.