I own a pair of Superex QT-4B's (Quad) & a pair of Superex Pro-B-V's (2ch). They look identical, except the QT-4B's are ivory color with a Stereo/Quad switch and two plugs. QT-4B is the best Quad phone I've ever heard, but there is still no seperation. Pro-B-V's (2ch) are the BEST headphones I've ever heard. Photo is Pro-B-V (2ch):