Quote:
Originally Posted by
nikp 
Isn't an ER4S an ER4P with the resistor?
Actually the ER4P is an ER4S w/o a resistor designed to play nice w/ iPods and such. Not so much w/ my ears. =P The ER4S was designed before portable DAPs were cool. Ipods became 'in' so Ety took the resistor out. The 'P' is just less refined at the extremes, harsher and brighter up in the upper mids and treble (especially the sibilance zone) and a bit boomier in the low end. The graphs don't deviate that much but it's enough for me that I can listen to the 'S' for extended periods and the 'P' for only 10-15 minutes.