Which brand of headphone is a military headphone? Someone said military headphone better than audiophile headphone such as Stax omega Is it true? Where can buy military headphone?

Which brand of studio headphone suitabe for SACD mastering? I have some choice: Stax omega II, Grado RS-1 , ultrasone HiFi 650 , Sennheiser 650.Sennheiser HD 25 II, beyerdynamic DT 880 , beyerdynamic DT48 Which one produce clean ,natural and balance sound? What is the differnt...

What is the different between Grado PS-1 and RS-1 headphone? I know PS-1 more expensive than RS-1. What is the performance of Grado Ps-1 headphone? What about Grado RS-1 headphone match grace design headphone amp? Can this match better than Stax omega II headphone with Stax 007 solid...