How to make a fixed attenuator for headphones

My ES2's are much too sensitive when using plugged into my ipod, the background noise is very noticeable, and I have to keep the ipod turned almost all the way down or it is way too loud.  I'd like to have an inline attenuator so that the background noise is reduced, and I can turn the volume up on the ipod to compensate.
 
I had one of those inline volume controls at one point, but the sound quality suffered, and it crapped out after about 2 months.  I have soldering skills, and I'd like to just solder a few resisters to a cable, cover it in heat shrink and call it a day.  What I don't know, though is the best value of resisters to use, and how to wire it up.
 
So, does anyone here have some suggestions?  My guess is that I'd want around a 10dB reduction, but even as low as 3dB would be helpful.  My main concern is to not lose sound quality (I've got other headphones that don't need to be turned down, but don't sound nearly as good).  Thanks!

a good early head-fi thread: http://www.head-fi.org/t/198828/the-hissbuster-for-sensitive-headphones
 
for the Westone E2S the numbers I find are 119 dB/mW and 27 Ohms - the "dual driver" can be a potential problem with any crossover giving impedance bump/dips that needs really low Z drive to avoid
 
the 119 dB/mW number is absurdly high ~135 dB SPL with 1 Vrms and the 27 Ohm low Z of the headphone
 
 
if you wanted ~120 dB SPL clipping level with a common DAP ~ 1 Vrms drive then you would want ~ 1:6 division ratio
 
even lower SPL, 110 dB can be considered fine for most listening "Audiophile" situations, 100 dB peak is OK for all day background listening at <~ 80 dB average SPL
 
 
higher attenuation ratios allow lower divider output Z - fewer interactions with multidriver iem impedance bumps, 1:10 for divider output vs nominal drive Z is a practical goal
 
at ~100 dB peak SPL from 1 Vrms you could use a 100 Ohm : 2 Ohm divider with the ES2
 
 
another approach I keep pointing to is to use step down audio output transformers: http://www.head-fi.org/t/553094/continued-sidetrack-discussion-from-tiniest-portable-amp-i-can-build-nikongod-microtransformer-based-impedance-step-down-box
 
[edit: looks like a little cross posting...]

Best thing on earth for IEM's 
 
http://www.head-fi.org/t/553094/continued-sidetrack-discussion-from-tiniest-portable-amp-i-can-build-nikongod-microtransformer-based-impedance-step-down-box
 
IMO, of course. 

jcx, that hissbuster thread is exactly what I was looking for.  I don't know that I followed the rest of what you said, but now I have something to work with.  Thanks!