Good ol' linearity has vanished on the 5:
This curve did not look that way while Jobs was alive.
You have not really understood something unless you can explain it to your grandma.
Please read the description on top. Chain used was Ultimate Ears Triple.Fi 10.
And the frequency response graph is the exact graph of the Triple.Fi 10 frequency response. You need a flat IEM to get a flat FR curve in RMAA.
In the interest of fairness, the iPhone 4 looks like this:
And here's the iPhone 4S:
Neither is completely flat.
Here's the impedance vs frequency curve of the Triple.Fi 10:
Edited by Bill-P - 10/10/12 at 4:15pm