Oh my goodness. You're really going to go there. :-P Are you serious? :-o I can't make those assumptions. And I shouldn't have to. If you say that, than I can tell you that everything he said is complete bologna, because I could have my ety using a different filter, tips and an amp with a custom bass boost mod to make the er4s the exact signature of the phone he likes. That's ridiculous. If you or he had said that in the first place we could have compared them on that level. Otherwise, why would someone assume otherwise? Sorry to be blunt, but that's absurd. We've clearly indicated if we modded out tips, inserted them a certain way or used filters (i have not).
You can't compare an er4p to another headphone and then later say "oh yeah i'm using the 75 ohm adapter". Then you're essentially comparing the er4s, not the er4p in terms of your mod. And as it is understood among all hi-fi IEM users and manufacturers, device output impedance that changes an IEM is not designed as a desired trait. In other words, IEMs are designed for output impedance as close to zero as possible to get the sound that was intended by the manufacturer. There is no other way to make sure customer get a consistent controllable sound. Most manufacturers will tell you they designed their IEM for a 0ohm output impedance if you simply ask them. I know. I have.
As for sources, again, most people know you need to get as low of an output impedance as possible and strive for this. That isn't to say someone can't get an amp with a higher impedance in order to try to get a certain characteristic. But you can't use that as an argument unless you specify all of those details to begin with.
Continuing like this is pointless. People aren't using valid arguments or comparisons. If you want a certain sound, fine. If you want to compare a certain sound, find. But do it relatively and logically. Fine, he has a modded, plugged hole, impedance adaptered, deep tipped ue900. Yes it's "closer" to flat now. :-P
Put the adapter aside, I don't have a graph for it, but the differences will effect the 2-5k range dip (impedance vs frequence graph shows this: http://rinchoi.blogspot.com/2012/10/ultimate-ears-ue900-general-analysis.html). So it'll make the dip slightly worse without the adapter. Still, everything else is linear with the HF5 graph and ER4PT graph as well.
So put the impedance adapter aside for a second. We don't actually need one. That said, it's still quite linear once the pinhole bore is filled. It fills itself if you don't clear out your ears daily (the norm of the people in the world don't do this daily, so it's assumable).
That's all I'll say about it. I've obviously hit a sensitive spot, I'm sorry.
EDIT: actually, I do have a graph for it, I posted it already... It's RAW not compensated. If you compensated it, it'll look very similar to the one I showed you before (with the 100 ohm adapter), although not exact (effects the 2-5k range).
Edited by tinyman392 - 4/6/13 at 10:27pm