A 5.1 on a headphone is more of a gimmick than actually is. However, a properly designed surround headphone can be of two things, one with specifically design multi speakers or the left and right speakers with its own sound driver aside from the sound card. Both will give you a simulated surround. Unfortunately, that discussion is debatable since 6 speakers, properly positioned is the same as 5.1 system from full speakers. Arguing factor is we only have two ears anyway. Therefore, the headphone is a true surround sound in close proximity and normal 5.1 speakers is…. So one with two speakers can now be argued to be a true surround since it produce similar characteristic given how we perceive the sound wave when it reaches our brain. Base on that reasoning then we can now bring the Surround Soundbar as a true surround since it is hard to pinpoint where the sound is coming from. ect. ect.