With no warranty left, decided to rip into the crappy Koss phones on the Excal and get rid of them. Transplanting the transducers into a pair of Grade5 Peltors.
Result? zero ambient noise leaking in, even in a decent wind. Even the tiniest whisper in the threshold is audible - And they're a damn sight more comfy!
Link on the howto is here:
http://www.youtube.com/watch?v=hVRtlsHVsjgNo tools needed other than a pair of side cutters (not having a Dremel), bit of hot glue and a small screwdriver.
As someone who picks up a hammer by the wrong end, then cuts themselves on it, if I can do it, it's easy!
I found it a lot easier to remove the endcap from the Excal control pod rather than be tethered to the detector, but recommend bagging the cap to prevent it attracting crap on the seal.
I am now authorised through experience to echo the sentiments of almost every other Excal user on the web that the yellow Koss phones are shite
Brings a new turn to the phrase "Silence is Golden" :)
MW