Subwoofers? I don't think so.
You generally don't find real subwoofers with anything less than a 10" driver. You could make one with a 6.5" driver (or possibly smaller) with a large cabinet, properly tuned. My guess is that two of those cabinets, properly braced, would weigh in around 200 lbs. for the pair. Not including suitable amplification which would weigh another 30-50 lbs. If you want to go portable, add other 75-100lbs. of car batteries for suitable power.
It would be inconvenient to have two subwoofers strapped to my head that weigh more than I do.
If you want deep bass, you need to move a lot of air. Headphones rarely have more than a 50mm driver. They can't do it. It's physics.
I run speakers for deep bass. Headphones can't do it, but I still enjoy the ones that deliver a lot of clean bass. Or "bass light" to a lot of people, but I don't like sloppy, muddy bass.
Anyhow, whatever Skullcandy is doing is just a gimmick. Don't buy them. Get a good pair of headphones and look to speakers if you want truly low bass.