Exactly my thoughts too. With the bass set to minimum the Layla's are as dead neutral as I've heard. Any "less warm", they'd be on the cold/bright side of neutral.My source amp/DAC is primarily the AK100II, but I've had similar results from my GD-X Mk2 / Metrum Hex.
Actually it is flat. You're confusions graphs with a HRTF applied and not applied. Measurements are part of the story, listening is the other part, and I really like how they sound, totally agreed here!