Does the flat phase response affect SQ and is it audible? One more question, why Sennheiser/Beyerdynamic/Focal are not using graphene coated diaphragms?
I see a lot of new earphones with new exotic materials being used in ch-fi. Is this just a new craze or they are really good? Many of them are very cheap. For example, Senfer PT15 is only $9.