I'm quite glad I gave these intriguing "Bi-Metal" Film Dynamic Diaphragm In Ear Monitor Canalphones a chance. Mine are named "smooth operator". With an awesome Frequency Response range from 8 Hz - 25 kHz, these things really sing well. They are very smooothe, round, laidback, open, bass-ey, sub-woof-ey, and fun. Non-fatiguing. Great for all round listening.
Here's the skinny:
Your stock tips are going to seal badly. Treat yourself to a pair of Phonak Audeo Perfect Fit Earphone Silicone Tips in Small from AudéoWorld PFE Shopping Cart
and once you've unrolled the sleeves inside out,
so they look like this ---> D==
You can squeeze them at the halfway point and wedge them over the rather large treble nozzles of the HA-FX300. Once on, paint clear nail polish around the bottom of the sleeve and driver junction to form a seal so they won't come off in your ear (for safety's sake)... How do I know, hmm... funny you should ask.
Anyway, it's a good idea tm.
Then Unroll them to normal so they look like this ---> =D
and you're all set. Let the Clear Nail Polish dry and cure before playing with them.
Here's a link to my initial review...
LINK ---> http://www.head-fi.org/forums/f103/n...ml#post5657609