Comparing the bass of an open back to a closed back isn't a fair comparison. I think the comparision should be Stealth against Stellia:The Stealth has a ton of bass.
Stealth = Green
Utopia = Red
You're probably not getting a good seal for some reason.
Mine hits nearly as hard as the TH900.
The Focal Stellia has a lot of bass impact and rumble. The DCA Noire had in comparision almost no bass impact and sounded really flat in the bass department to me. Other headphones like Focal Radiance, Meze Liric lack in comparision to the Focal Stellia with bass impact/rumble, but had much more bass in quantity to the Noire.
Whats your impression of the dca stealth in terms of bass impact? The Aeon2 Noire should have much more bass in quantity from the FR.
Thats only my impression