Here's what I had about the differences:
"The PJB H850 has a completely new design transducer to cope with the extreme punishing low frequencies and dynamics of a bass guitar.
This transducer is unique to the PJB H850 and not available in any other headphone.
To achieve the desired performance, they used a more powerful neodymium magnet, a slightly larger voice coil and to keep the moving mass low, they opted for copper clad aluminum single layer, edge‐wound ribbon conductor.
Also, the rear damping chamber is far more effective than the Edifier headphones.
Another thing is that the PJB headphones have a much flatter frequency response across the whole audio spectrum and consistent in manufacturing to within =/- 2dB.
The Edifier headphones have a very peaky response from 5KHz on up and that is due to the fact that there is far less damping inside them along with a lower cost diaphragm and two layer round wire copper coil.
The Edifier brand is a low cost consumer brand and the products designed for them are built to fit specific low price points."
Sounds like they are pretty different to me. . .