The Fearless Audio S8Z was called a detail beast by a well respected reviewer, and I would agree. Here's the thing about details, if they are intentionally in the mix, these IEM's enhance them in ways I've never heard before. If the music is not mixed well, the bad stuff is more apparent and well, the music sounds worse.
I don't believe that sound stage is something that can be influenced by headphones. I believe that sound stage a result of the way the music was mixed and mastered. What the S8Z allows is tremendous separation between dynamic range and frequency that gives the listener the feeling that they are sitting in the music.
With well mixed music, the bass is impactful without being overbearing. It's tight. It goes low. It hits as hard as it should without feeling overdone. In a word it's confident.
The high frequency range is just crazy. I hear the way a stick hits a cymbal like I've never heard before. I don't know how Fearless achieved such control with high freqs but no matter how much is going on up high, it sounds complete but not hot. There is no sibilance. None.
Mids weave themselves seamlessly in the mix and vocal range is equally as pleasing with male or female registers. I've been hearing details like breath, mouth squeaks, and accidental mic bumps that I've never heard before on tracks I've listened to for years.
If you are looking to explore your favorite music in a new way, and hear details that you haven't heard before, this is the set for you.