Can I use in-ear headphones with Reference 4? Viesturs Updated September 16, 2019 12:13 Follow No, in-ear headphones are not supported at the moment. Related articles Where do I ship my headphones for individual calibration? What is an individual headphone calibration? I received my individually calibrated headphones but there is no individual calibration file. Where do I get it? (Reference 4.2 & legacy versions) How long does it take to calibrate my headphones? Can I use my own microphone calibration file? Comments 0 comments Please sign in to leave a comment.