The SW-8 looks like a "borrowed" design to me.... but with an entirely different driver.
It looks more than a little similar to the tSC ASW-8... I have one, and the dimensions look to be identical. Not only that, but the amp ratings are also identical, as is the layout of the amp.
The tSC ASW-8 was a clone of the Energy ESW-8 as far as any owners could tell (I owned the ESW-8 briefly and returned it to get the tSC sub for less $$)... lacking only the ribbed surround found on the ESW-8. Otherwise, the amp, driver material, and cabinet appeared to be the same (although different cabinet feet).