Crosspost with the FXT90 thread on Head-Fi:
Bit the bullet on a pair of JVC HA-FXT90s to replace my dead but not forgotten Panasonic RP-HJE900s. Before those, I had some Etymotics that died far too quickly and were rather quite forgettable (ER6s I believe).
Disclaimers: I am probably still giddy over the new toy (I have been IEM-less for far too long) and these have not been burnt in at all. I listen almost exclusively to electronic music, focusing on House although I'm really open to anything. Songs are either streamed via YouTube, SoundCloud, or 320kbps mp3s from my small personal collection directly from either my desktop PC, Ultrabook or smartphone.
Long story short: I'm no professional audiophile, and this isn't an intensely analytical review. I'm looking for something I can enjoy casually without having to break the bank or encumber myself with a ridiculous setup. Nevertheless, here are some initial impressions if anyone was interested. So far: a mixed bag, but promising.
To begin, these are not basshead IEMs - the HJE900s definitely win in that arms race. Nonetheless, the bass is very satisfying. What the FXT90s lack in sheer quantity, it makes up for with an impressive attack free of any bloat, coupled with a low-end rumble that frankly, given the rest of the bass, absolutely blindsided me. A supremely confident purr that provides excellent backdrop to the lively impact of the mid and upper bass. That being said, when that growl isn't there, that higher end suddenly feels very anemic, naked even. Unfortunately, the rest of the frequency does not exactly mask this sore spot.
For most people, I would imagine the mids would be considered slightly "warm". For me, who has primarily listened to nothing but "warm" headphones, I feel the mids are actually quite recessed. While the FXT90s don't hide the mids in a dark closet, no song I've listened to can bring them to the front over the hard-punching bass or the sparkly treble. As much as I want to throw the "analytical" word down, there is still an evident touch of warmth in the lower-mids and a tinge of airiness as the mids approach highs. In comparison, the HJE900s definitely carried its bucketloads of bass through to the mids, wrapping the entire range in silky warmness that let songs ease on through much easier.
Once it does get into the highs though, that tinge turns into a downright crackle. Like a shot of crisp winter air down your nostrils, the upper end is refreshing but also chilling. People have also said the HJE900s are bright, but I only felt that way about the very tip of the treble response there, whereas I feel brightness is currently much more endemic in the FXT90s. The other thing to note is that there is a definite hint of sibilence, which if it doesn't go away via burn-in, might be grating, but only on extended listening sessions. Overall, there's a clear emphasis on the treble that allows the high notes to really dance on top of everything else.
I've never been much of a soundstage fanatic, but I can definitely hear the difference with these headphones. But it's very hit or miss - certain songs can really isolate and bring out individual aspects, whereas other songs the lines are very much still blurred. This brings me to a point I've been meaning to bring up - I don't think these are very forgiving earphones. I've mentioned that I stream a lot (most) of my music - the HJE900s would sometimes turn songs ugly, and I suspect that much of the same is going on here. Poor sound quality may be causing a lot of details to be lost in translation. After more burn-in, I really want to see what impact bitrates and sources have on this.
At $89, these are a pretty amazing deal. That being said, I have to see how that bass and mid resolve during burn-in - as they stand now, I would really have to convince myself not to return these for something more refined.
Anyways, just my $0.02.