Actually, if anything, the GR07mkII may have slightly more treble over mids, than the ER4S does, overall. In other words, the ER4S is slightly less tilted from mids to highs. You must keep in mind that I didn't listen to the stock GR07; I listen to it EQ'd. With my EQ setting, it's just as analytical and "cold" (I don't like these words) with the same treble quantity as the ER4S, and the ER4S still resolves more details effortlessly. The ER4S's presentation is incredibly realistic and moreso than the GR07, especially in the 3D soundstage, where each instrument has its own space and doesn't smear into other sounds as much, which also creates a clearer image.
What you're hearing as more decay, I think, is actually the GR07's greater sub-bass quantity. However, if you EQ these phones to have the same flat bass response, it becomes clear that their decays are very similar; while ER4S still resolves more bass detail.
I only listen to iems with flat eq, so I get the sound signature that was intended by the manufacturers. It's pretty obvious that you can EQ an iem to be close to the signature of another iem but it will never be the same. It's all down to thechnical ability, tuning, the housing, the depth insertion and a lot of other suff. The low treble of the gr07 is slightly hot but that's all. You can try to Eq to make it sound analytical but that's not a fair comaprison - it's like going the other way around. What will be you opinion if you EQ the er4s to sound warm and sweet? It will still not have the natural presentation and the dynamic range of the gr07 and you can't fix its decay times, bass body and texture. Yeah, the er4s will still give you more detail but that doesn't make the sound realistic as analytical iems I made for analyzing. It will never sound as musical as the gr07. For that matter even the brainwavz b2, which has great treble and superior detail retreival to the gr07 and you might call it analytical, is a lot more musical than the er4s. It's funny your talking about 3D sounstaging as for me both gr07 and er4s are lacking in that matter - soundtage is not just instrumental separation, it's width, height, depth and positioning. I'll have to mention again the B2, which has a lot more airy and spacious presentation than the er4s. So for me aside from instrumental separation sounstaging isn't one one of the er4s' strong suits and drfinitely not one to quote and brag about. You have to put EQ aside and realize that they are competely different iems that are not meant to be competing against each other. Each one has its strong and weak sides and while I do love the er4s it's definitely not the do-it-all and the most versatile iem around.
Edited by kova4a - 12/6/12 at 12:22pm