Well, that would be the W4's primary deviation from neutrality. +4db bump at 125hz or so. Yes, the bass on the Sonys are flatter, with no sudden lumps down there. EX1000 bass seems reasonably linear, just shelved up, hence some warmth. Less mid-forward than the UM3x and brighter too. UM3x needed a treble boost, really, and the W4 still isn't bright. The opened-up stage is another thing the W4 has for it over the UM3x. Fixed.