Similar case here.
Already listed my TG!334 and BTG Starlight in the local forums
a little feedback on my adventure in resistor land.
Rin Choi suggested a 100ohm resistor added. I'm such a fan of all the work done on the MRO blog, but here I'll have to disagree.
to my ears, even 30ohm lowers the trebles too much. I'm all for the taming of the bass part, but not at the price of the trebles, else the 334 loses some of what makes it good.
played with combinations of 3,5,30,100 ohm, my ideal result was 5 or 8ohm depending on the source, I liked 5ohm better on my sony but it's own output impedance is something around 3ohm so no wonder here ^_^.
with this 8ohm (on 1ohm or less sources) I find that the biggest impact is that it lowers the sub bass a good deal without yet making too much damage to the rest. and by doing so does give a feeling of faster and tamed bass (the real purpose of all that mess).
I'm pretty happy with the result here, but to be absolutely honest, it's useful to me only on my sony A865 that doesn't have a negative EQ under 400hz. else I can get something very close just with EQ -3db in the bass region.
I've made a little attempt at calculating the maximum variation for 8ohm added from lowest and highest impedance points of the impedance graph of the 334 using simplified spells from "he who must not be named" Nwavdemort, and it gave me something like a 2.6db maximum variation. I'd say it doesn't fall too far even if I didn't graduate from magic school.
anyway it was a fun experiment, and the 334 is actually my only IEM to get (to my hear) any benefit from an increased impedance. most dynamic driver didn't really care (except that I had to push the volume to compensate). all other BA drivers had different reactions (logical) but always bad ones. Parterre really don't like increased output impedance!!!
/me iz gonna get exiled to soundzkaban science priso... section of headfi.