When I finally got both ports to minimum, the phones sounded good, in fact way more than good. It seems as though the ports affect the shelving of where the bass really begins to hit, and by turning them down, one can still hear very impressive sub-bass without delicate mid and treble detail being masked. As the ports are quite sensitive to movement, I assumed that if they weren't set to allow the exact amount of bass on each, imaging would suffer, so using a 50hz test tone and a dB meter designed for IEM's, I matched each side to the exact same decibel level.
My settings end up having both ports very slightly open, perhaps 1/16 turn. For the type of music I enjoy (classical, vocal, acoustic and instrumental) the sound is, to my ears, excellent and quite capable of holding its own with the "big boys". The treble adds enough sparkle to make brass really sound like brass and to present the sound of cymbals, snare, high-hats, etc very realistically. I hear very little sibilance and what I do hear, I feel sure is present in the recording.
When I spoke with Aurisonics prior to ordering these, they said that the main differences between the 2.0 and 2.5 is that the highs are a bit less pronounced resulting in less "tizz" and the bass ports affect the level of the sub-bass more than the mid-bass, allowing a good fundamental foundation to the music without mid-bass bloom.
Overall, I consider the sound to be such that one doesn't lose interest in what you are listening to. It is, when tuned properly, both accurate and exciting. The more I listen to the 2.5's, the better I like them. IMO, it is a huge plus to be able to adjust the bass level to ones personal preference and for music that doesn't require huge amounts of bass, it is still good to be able to almost feel the sub-bass, giving the music a really solid foundation without masking details further up in the frequency spectrum.
I did try several different cables, including the Whiplash TwAu flagship, but to my surprise, I liked the stock cable better than any I tried.
My nits are relatively few: The cable really doesn't set far in the recess, in fact the recess is not very deep. I haven't experienced any problems with this so far.
Cosmetically, it seems as though the matte black finish might be prone to marring or scratching if stuffed into a pocket with keys, loose change, etc.
I do not like any of the included tips. They seem to be made of some type of material that is rather sticky to the touch and is not soft enough to provide a good seal for me. I ended up using large-bore silicon tips that provide an excellent shallow seal. The wide bore tips move the soundstage closer, while narrow bore tips move the soundstage further away but also narrow it some in comparison to the large bore tips. Imaging is quite good with both, once the bass ports are set to deliver matched bass levels.
Vocals, especially female vocals are a bit more recessed than those in my ASG-1.3S and Final Audio IEM's. It isn't really that apparent until one makes side-by-side comparisons.
The overall build quality is OK, but not up there with the likes of the Ref.1, StageDiver SD3, Final Audio, etc. When one first picks up the 2.5's, the expectation is for maybe OK sound but probably not TOTL performance based upon the look and feel in the hand. Fortunately, first appearances are not always accurate as the SQ is right up there among the best.
For an "all-arounder" universal, the ASG-2.5 should certainly be on one's short list for serious consideration.
Edited by HiFlight - 8/7/14 at 6:09pm