I've auditioned the Pandora Hope VI/Sonorous VI (the name was changed after a trademark dispute with Pandora radio) extensively, and they sound absolutely fantastic to my ears. This is the last full sized headphone designed for Final Audio by founder Kanemori Takai before he passed away last year. He thought of himself as an artist, and his designs, or rather the way his designs rendered sound, to be his works. This philosophy is the hallmark of the Hope VI. The headphone sounds as though it were put together with the idea in mind that audio equipment should be judged by how well it conveys the emotion of the music to the listener, and I have never heard a headphone which does this as well as the Hope VI.
Tonality wise they sit sort of in between neutral and v-shaped, in that the extra bass thwack and top end energy don't so much as draw attention away from the mids as they do enhance them, making them fuller, warmer, airier, giving them shimmer and sparkle, while still maintaining an organic, uncoloured presentation that to me approaches transparency. I think the best way to describe them relative to a reference point would be a SoundMAGIC PL50 with a modest smiley face EQ, but that really wouldn't do it justice.
Bass is not huge, but it's not thin by any means. Think maybe a 3-5dB boost. Although I didn't get a chance to do a sine sweep with them to test extension more formally, they sounded absolutely bottomless with every track I threw at them. There is great texture and detail down in those depths too, although those looking for an analytical bass presentation should look elsewhere. Bass notes aren't boomy or loose by any means, but they're not planar-tight either. This doesn' feel like a failure of the headphone though, it seems like a conscious choice made during tuning to give kick drums and the like a little more weight and prescence.
Treble is fast and detailed, and carries great energy and air. Extension into the upper ranges seems effortless and although I wouldn't call the treble harsh, I wouldn't say it's been smoothed or sweetened either, like one might say of the HD650. Its timbre is more honest than anything.
Aside from the delicious tonal balance, it's absolutely dripping with detail and the soundstaging is immense; not just "big for a closed headphone," as we so often hear, but really properly huge, and with immersive pinpoint imaging that sends shivers down my spine.
The only thing that irks me about the Hope VI is that although the highs carry plenty of sparkle, energy and detail, they can become fatiguing during longer listening sessions, and they have a tendency to not want to play nice with music that's been mastered sibilant. That being said, my ears are more sensitive to sibilance than those of most others I know, and when I hear the sound of my favourite music through the Hope VI, I know that the brightness is worth it. Oh, so worth it. I will definitely be buying into this drop (if I can muster the funds, fingers crossed), this really is my endgame.