- Jan 6, 2013
Are you sure about the measurement technique and the wired source? A 20dB dip at 2kHz would be drastically noticeable; on my headphones the 2kHz region is not noticeably affected when going between wireless and wired (LG V20 source). (Playing with EQ and adjusting by just a couple of dB at 2kHz I easily hear the difference - it's not a problem of my ears).
The measurements I was mentioning can be found here in the 2nd spectrum "Power Off - Diffuse field target compensated" https://clarityfidelity.blogspot.com/2016/10/sony-mdr-1000x-bt-nc-over-ear-headphones.html
They may have had a particularly bad dip in their set (email@example.com from a 95db baseline) but the low sensitivity from 1-3khz is seen in most graphs on various review sites. Cheers