DC Gold's background is building marine speaker drivers for lux yachts and super villain submarines. As you can guess, they've transitioned their sea-worthy technology into home speakers. The very unusual "spiderless" DC Gold divers are full-range affairs going the low sensitivity route. Behind the grill is some strange driver material that was only described to me as "proprietary" but appeared to be asphalt or some brand of black chewing gum I'm unfamiliar with.
Below, you can see an interesting space inside the speakers. While festive sprites held court at the show, I'm sure you can come up with other far more creative objects to place inside. Larger pic next page.