@Ninja Pirate
After reading some comments on Hype-fi many people have been trying different pads on the Nighthawk. I bought the Brainwavz Velour pads and chucked em on.
Have to say it's quite a shocking change. The mids breathe now as when I was doing AB testing with open phones I found that boxiness would bother me a bit.
So the Brainwavz Velours thin the sound out. Mid bass is less boomy, more air seems to escape so it's not as warm. I'd say it sounds as warm as my 650 now maybe less where as before it would sound a little too warm at times.
Mids seem to have better clarity, they are still not as intimate as the 650 but they are about a similar position to the Philips X2 but with a slightly smoother tone to vocals. They sound more aggressive, the treble doesn't sound dark at all due to the big bass taking the attention from everything before. Bass extension seems to hold up, maybe slightly more rolled off but it's difficult to tell as I'm still adjusting.
So far I think it's a good change and I'm shocked they didn't use Velour to begin with as the driver of the Nighthawks is actually very good.
I do think a bit of treble roughness has come through but it's a more refined treble than many in the price range and under. reminds me of a smoother, slightly less aggressive D7000.