Hi HF,
 
I'm a little embarrassed to ask this question, since I've been a long time audiophile and have so much gear, BUT...
 
Does the impedance of a headphone depend on the internal drivers or the cable? That is, I'm thinking of having my Ultrasone Edition 8 Recabled either by Moon Audio or Whiplash, but I want to keep the impedance the same at 32 ohms so that I can still drive it off my iPhone on the go. Will a recable impact the impedance of my ED8's?
 
Also, it's probably going to be terminated in a 1/4" jack for home use. What's the best quality 1/4" to 1/8" adapter cable out there that won't reduce the sound quality of my soon-to-be upgraded cables on the ED8 (so that I can plug it into my iPhone)? Right now all I have is the stock one that came with my Sennheiser HD650 and the cheap $15 Grado adapter cable.  
 
Thanks so much in advance!

Ideally the cable will have zero impedance. If the cable has some impedance, you could think of that as being added to the output impedance of the amplifier. Sound is only generated by having voltage drop across the driver, not the cable or amplifier output.
 
I don't know about the jack adapter. I'm not sure why you would want to do that instead of terminating it to 3.5mm and use the opposite adapter.

Thanks for the info -- I'll keep that in mind. Obviously I never paid any attention in AP Physics E/M. Can someone else confirm this?
 
I want to terminate to 1/4 because the vast majority of the time, it'll be for home use. The ALO Cable adapter is $99, a similar Cardas Adapter (cheaper looking, but still made by Cardas) is only $22. Help?