By depth I'm talking about along the x-axis, level with the eyeline. you know, across the face rather than down the face.
Soundstage placement can seem to change with volume. If you play something louder, not 100% always, but in most instances vocals would be more upfront. The senn mometum has a recessed midrange and this is unanimously agreed upon by all reviewers I trust the opinion of. Once the volume is turned up then this 'problem' is alleviated, but the user feels a thumping bass response and amplified beyond neutral levels in the upper mids/highs. The midrange sounds more upfront now, but that's because of volume.