Just wanted to make a post commemorating the IE900 and some further thoughts I had on it. I really liked what I heard when I demoed it at the Sennheiser SF store, and I just couldn't get it out of my mind, so I ended up purchasing my own. Not really going to talk about the build/accessories; I'll save that talk for the actual review. I'll leave it at saying that while I appreciate having three separate cables (and they feel great), memory wire was not the way to go haha.
So about the actual sound...
Here is my personal unit graphed:
There's not much that I haven't already said about the bass response of the IE900, but just to ram the notion home, it is nothing short of excellent. I see a lot of talk about "dynamics" when it comes to bass, but the reality is that the vast majority of IEMs that I hear do
not have good dynamics. That's neither in the bass, nor much less as a whole. Dynamics are indicative of gradations in volume, and within the context of bass, a bass response should present itself with a sort of "bounciness" (at least to my ears) if a transducer is replicating them properly. Of course, this depends on the music you're listening to too. But simply put, the IE900 has some of the best bass dynamics that I have heard. Other intangible metrics of bass, from texture to decay, are also right where they should be for a world-class bass response. The tonality of the bass shelf itself is largely sub-bass oriented with a hint of mid-bass to inject an extra kick of fun that's right up my alley. It's hard to believe that a 7mm dynamic driver is pulling off a bass response this good; regardless, it would not be an understatement to say that the IE900 might have one of the best bass responses in portable audio.
The midrange is where the IE900 stumbles: It has no pinna compensation. Well, that's not quite accurate. It has
inadequate pinna compensation and then opts to recess all of the upper-midrange. This results in a decidedly U-shaped presentation, wherein a lot of stringed instruments - for example, guitars - sound soft, slightly muted, and lack initial sharpness of pluck. Piano also gives me the impression that the keys are being pushed into a mushy pit of tar. If there's a saving grace to this midrange, it's that 1) I actually
like a slightly recessed (read: but not this recessed) upper-midrange, and 2) it aptly kills any sibilance or harshness that might otherwise be present. Still, while I know it's an intentional tuning decision (as all the other Sennheiser IEMs have it), frankly, this just needs work. The egregious recession from 2-5kHz also lends to a disconcerting center image with which it's difficult to pinpoint, positionally, where vocalists that usually token the center come from.
Criticism of the midrange aside, I don't think I gave the treble response of the IE900 enough credit in my original impressions. I personally found it somewhat "spicy" when I demoed it; perhaps that was due to listening at louder volumes than normal at the storefront. Anyways, the IE900's treble response is characterized by a plateau from 7-9kHz in the mid-treble which lends to copious amounts of sparkle. It is remarkably controlled tonally, sloping into and off of this plateau without any egregious peaks or valleys. Thus, while you definitely have a brighter treble response, it is by no means harsh to my ears. Extension is superb, extending well into the 15kHz+ regions with sufficient presence. Attack is well-defined and sharp, and honestly, while some might still find it too bright, I find little fault with this treble response on second listen. Consider me a happy camper.
In general, the IE900 is also one of the most technically competent DDs I've heard, comfortably playing within the realm of even many full-BA and hybrid setups in its price range. Obviously it's not playing with the
top dogs of this price range for technicalities, but hey, that's not too shabby! There is a good sense of vividness to transient attack and note definition is within flagship parameters. Dynamics on the IE900 are also solid; it certainly doesn't sound compressed. But it's clearly not world-class for this more latent intangible. The IE900 mostly captures crescendo/decrescendo swings (take for example a steady rise in volume as an ensemble picks up the pace and more instruments enter), but it can get "caught off guard," so to speak, when it comes to more abrupt, explosive swings into loudness. This is mostly just me being a picky asshole; of course, I trust that's why most are reading my reviews. A broader concern would probably be the IE900's imaging chops. As I alluded to earlier, the center image is just...not really
there, so there is a lack of perceived soundstage depth. Staging also doesn't extend much further laterally or horizontally; the IE900 is a good way off holographic in my opinion.
My thoughts right now
Overall, the IE900 is clearly not perfect. But I could say the same for anything else in portable audio; you inevitably have to make trade-offs in this game. It's also important to consider context - after all, this is a single-DD IEM. That in mind, as far as I'm concerned, this is the best single-DD IEM that I've had the pleasure of hearing so far. I can usually tell pretty quick if an IEM is going to make the cut in my collection (benefits of hearing so many IEMs and being an absolute nitpick), and I get the feeling that the IE900 should have my single-DD itch scratched for a good while. I'd say I'm content with this purchase.
