Could be. Or it could be a custom OEM version made for ADAM to their specs, Peerless and most other driver manufactures do a lot of their business making custom OEM products for speaker manufacturers
Wouldn't be a surprise. The SLS woofers are good. Genelec also used or at least commissioned one (the 10" variant) for one of their subs. They sold their excess to Parts Express.
Prefab subwoofers are almost always extremely bad values.