I am a reviewer, so you can take my comments with a grain of salt if you wish.
I heard both the Sapphire and the Aventis Phobos two weeks ago at a dealer. The rig, aside from speakers, was:
T+A cdp, T+A tube pre, Transparent Opus MM (top of the line at $30k) speaker cables, Clayton Audio monos.
With that equipment, in that setting, the Sapphire was bright and very forward sounding. The Phobos was more tempered in that respect. Both use a marginally sized midrange, which contributed to the more "intense" sound as opposed to a relaxed or laid back sound, in my opinion. For some time I had used the Chapman Audio T-77, which has twin 5" midrange, and even those I felt had too much bite. I lean toward a larger mid, such as a 6.5-7" mid to remove that stridency. Tonally, I preferred the Saphhire, but not at the expense of the more stringent treble. They both had excellent clarity and crispness, but the low end suffered.
Regarding bass, neither one had low end that I would characterize as overwhelming for a $16k speaker. The Phobos was fairly weak in this respect, and the Sapphire was more respectable. The aesthetics of both were outstanding, but both only sounded more balanced and full range when the accompanying REL sub was in the system. I turned the REL sub off when listening to both, and in both cases the bottom dropped out completely, and the midrange and treble brightness was more pronounced.
I have no doubt that with different equipment and in my listening room I could address much of these issues. I believe that I could find superb sound with much different electronics and cables, but those looking for a laid back, mellow presenation should use caution in approaching them.
