All - I've read just about every thread/post I could find on the Forum on the T5p, and what I'm trying to determine is whether it can be driven "well" by an iPhone 4S. My point of comparison is the Senneheiser Momentum (primarily because of its comfort, and also because it appears to be one of a handful of headphones that folks really like that work directly with an iPhone). I wear glasses, so comfort is important to me, and in terms of SQ, I'm looking for something that has a lot of clarity and detail even at low volume (trying to preserve my hearing), even when driven by an iPhone only. I find that with the Momentum, some of that detail is lost at low volume, and as a result, I end up turning up the volume more than I would like.
I realize that the bass on the T5p isn't going to be the greatest without amping, but I could live with that so long as it were accurate and provides sufficient fullness and warmth to the sound at low volumes. For those familiar with IEMs, I'd want something warmer/richer than what you'd get from the Etymotic ER-4 (although the detail/accuracy is incredible).
I know that the T5p, as its price would demand, is a much, much better set of headphones than the Momentum under optimal conditions. But if it isn't that much better straight from an iPhone, then it isn't worth it to me. I'd get a portable amp eventually, but the convenience factor of not having to deal with one is important for my expected use.
Many thanks in advance for your thoughts.