It has been a long time since I started this thread. Coming from the Grado modding crowd I took interest in the Magnums, then V4s, since the drivers were freely available, came at an acceptable price, and could be used in all sorts of housings. I then proceeded into the planar world, among others, and sold my Magnums, since I ultimately found them too shouty and lacking comfort.
By accident I again took some interest in these types of drivers, doing work on some used SR125i and now Turbulent V5 drivers. I am also using a kind of DIY hybrid GradoBeyer pad, for which I am using some L-cushs (cut to shape) and Beyerdynamic DT25 pads on top.
In addition I have been using my measurement rig (calibrated mic, flat coupler, no compensation) in order to "verify" my mods. Below I am sharing my V5 measurements and mods.
Stock Turbulent V5 drivers, in a Grado wood cup, open back:
Finished headphone, black ebony cups with black and white ebony nuance, closed:
Cup and driver
Driver in rosewood inner sleeve, GradoBeyer pad
Measurement of the finished headphone, closed cup, internal damping. Very neutral sounding.
Internal damping change, a little less distorion in the mids. Very nice sounding, clean and fast.