It's funny, when i originally got these i thought they were so boomy and bass heavy, or a certain part of the bass spectrum. Someone else posted that he had returned them because he felt that he was strapping on two subwoofers and there were others who agreed. Since then they either burned in or my brain burned in because they don't sound so overly bassy anymore.
I think... over time, it's possible that as you put them on and pull them off, and due to environmental impact (heat, etc...), the ear cups get pressed into the plastic enclosure, or the plastic enclosure expands ever so slightly, and the very small openings are then made even smaller.
When that happens, the inside becomes more airtight, and then bass would be reduced.
That's my $0.02 on the matter.
On the other hand, when bass is not so overpowering, the ES10 does put out very beautiful vocals. I think it even beats the ESW10 cleanly.
In any case, I'll get my ES10 back tomorrow, and then I'll be able to definitively see if they are indeed similar to the W1000. If they truly are similar to the W1000, then most likely, I'll just keep one headphone and sell off the other one.
My ES10s (with the E**11 pads) are stuck in @dallan 's "before" scenario, i.e. subwoofers on my ears.
@Bill-P , tell me more about what I can do to salvage some kind of mid and treble response out of these things! Alternatively, someone make me a reasonable offer!!