Thanks to my always generous friend, DannyBai, for sending me his (well burned in) FXZ100 to audition. I've been listening with the ODAC & the Schiit Magni (as well as Leckerton UHA-6S MKII & Objective 2 amps) for a few hours. Here are some initial thoughts on what I've seen/heard so far:
The 100's build is fantastic. Looking at the size and shape, you might wonder how these would manage to sit in your ear.. let alone remain comfortable.. but it does both.. in quite an effortless manner. Its weight is sneaky light, it quickly inserts with practically no fiddling, it and remains suspended without causing any fatigue or stress. Impressive. The cable is excellent too. Smooth, tangle free, lightweight but robust enough for lasting durability. Identical to the FXT90's cable, if my memory serves me correctly.
While I'd characterize myself as a listener who prefers neutral to neutral-ish, monitor-inspired phones, I'm not biased against more colored phones (hell, I've owned and still love plenty of them). I tend to appreciate signatures in all shapes and sizes as long as they're cohesive and artfully tuned. With that said, I'll get the obvious point of (recent) contention out of the way: the FXZ100 is not a 'basshead' phone, IMO.
Is the FXZ100's bass emphasized? Affirmative. But it isn't so emphasized to make it the focal point of the sound. The bass is more boosted than what you'd hear from the GR07 MKII.. but less than what I remember hearing from the (midbass heavy) FXD80. Think FXT90-levle bass that's more linear.. and boosted up a decibel or two. As far as the Kelton technology/sub performance, I didn't find the performance particularly noteworthy. The 100 had terrifically effortless sub-bass response.. certainly enjoyable & impressive.. but in evaluating the bass response as a whole (texturing, clarity, speed, timbre, PRaT, etc.), I didn't get the sense it was miles more impressive than what I've heard from other high quality dynamic/dual dynamic, hybrid, or even multi-BA drivers. The GR07 MKII's bass more than holds it's own in comparison, IMO. Even the BA200.. while its bass might not extend down as far or punch as hard.. can, arguably, texture just as well, if not better. I found the FXD100's midbass, even when amped, to be a little loose and slow at times.
The FXD100's signature, while fairly balanced, is firmly grounded in the midrange. Instead of getting long winded with words (as I typically do), I can best describe the midrange as possessing a smooth, Grado-like signature (perhaps, more accurately, an upper-tier Grado.. also perhaps the FXT90). The mids are certainly forward and engaging, but they don't possesses a sharp upper midrange/lower treble spike (that tends to accompany lower-tiered Grados or the FXT90). The treble is positioned slightly behind the midrange.. but there's just enough quantity to give the sound a sense of balance. It's quite inoffensive and non-fatiguing as it starts to roll off (in my rough estimation) around 8K.
The FXZ100 sounds more FXT90 than it does FXD80. In that regard, the sound is richer, slightly warmer, and midcentric (vs the colder, v-shaped sound of the 80). There's definitely more in common between the FXD100 & FXT90 than the looks.. in fact, I'd say the 100 is a very noteworthy advancement on the FXT90's sound and technicalities.