Summary, First Draft:
The PRO 2900 offer levels of quickness, refinement and delicacy that their predecessors (the PRO 2500) do not. Soundstage is well defined, with individual instruments/performers placed "to a tee" in vibrant, 3-dimensional space. Bass is denser and delivered with more impact; reasonably clean, extended and articulate. A fairly even-keeled frequency response and touches of tonal sophistication round out the engaging sonic balance of Ultrasone's latest—and only—open offering.
That said, the PRO 2900 do not have the raw, un-hulled texture of the PRO 2500 (which, by the way, I have come to appreciate over the years), and in some respects can sound slightly distant or “abridged” by comparison (to the 2500). The PRO 2500’s soundstage, in addition to being more forward and a bit more saturated or informative in absolute terms, is also arguably larger and more diffuse by contrast.
The 2900—and to a greater extent than the 2500, I think—should benefit from an injection of upstream warmth: at the source (including the quality of the recording itself), at the amp and/or along the cable stream, otherwise their comparatively lean texture can be overstated, and their otherwise welcome qualities overstayed. In fact, given a warmer source, like the Denon/Denon combination [and what side of the bed I happened to wake up on], I tend to prefer the 2900 to the 2500. On the other hand, given a cooler source, like the Samsung/Linn combination [and/or another side of the bed], I tend to favor the 2500 over the 2900.
While, in my humble estimation, the Ultrasone PRO 2900 demontrate a distinct departure from the familiar "stock" or "house" sound of the PRO 2500, the PRO 2900 nevertheless bring to the table a vivid and refreshing counterpoint, an alternative just as technically adroit and musically satisfying in their own right. Based on preliminary dissection, these sonic differences are apparently correlated, in some measure, with design changes to the MU plate and re-sizing of the ear pads. (A more thorough side-by-side comparison, requiring further disassembly, is planned for a future date.)
To be frank, I am as-yet undecided on my preference for either one of the two. Each has uniquely satisfying merits of its own. In addition, having logged only about 150 hours on them so far, I am not convinced whether the 2900 have as-yet shown me their full capability. Therefore, God willing, I intend to complete another round of critical listening [between the 2500 and the 2900] after 150 more hours of run-in with he Pro 2900.
Edited by pataburd - 1/6/12 at 9:25pm
