We used these headphones on a running from September 2004 to December 3 musicians and 2 engineers Returns (singer both pro E5, same headphones but directly in his Mouls footprint, whereas E5 fit into the castings, but may be utiliss without, by means of foams). I used it to make returns of rgy facade turns on the same solo artist.
This is an excellent earpiece which presents the advantage of providing a real serious (nothing to do with the E1 and E3 of the same manufacturer).
It is very accurate. A little "stiff", not very rich in the treble, but very accurate.