Alright, i've been reading about output impedance, and i understand that with a relatively low output impedance there is more electrical damping and the headphone offers up a more accurate sound.
So as i understand it with the etymotic er-4 series the drivers are the same; the difference between the er-4s and er4-p is an impedance is added in line, which is essentially duplicating an output impedance. How is it that increasing the output impedance improves the advertised accuracy?
Here's the linkie i'm referring to
Thanks for deconfusing me!