Review written by @Precogvision
Noble Audio is an older boutique brand that’s best-known for their stunning, handcrafted IEM shells. They enjoyed moderate success with their “K10” lineup several years ago; however, it seems like they’ve struggled to capture the same magic in an IEM since then. Enter the Sultan. The Sultan marks one of two IEMs - the other being the Zephyr - that Noble has brought to the market in an effort to recapture lost ground. It’s also their first tri-brid IEM, making use of a single DD, four BAs, and of course, two of the infamous EST drivers.
I’ve reviewed a couple of Noble’s offerings in the past, and unfortunately, each time I came to the conclusion that while quite pretty, their IEMs’ actual sonic qualities were more lackluster. So once again, I’m forced to ask myself: Does Noble’s latest flagship have what it takes to propel the brand into “more than just a pretty face” status? Let’s take a look.
This unit was kindly provided for review as part of a tour organized by AudioTiers.com. Thank you! At the end of the review period, it will be sent to the next person in line for the tour.
Source and Driveability
All critical listening was done off of an iBasso DX160 (volume ~10) and A&K SP1000M (volume ~30) with lossless FLAC files. The stock silicon tips and the stock cable were used. The Sultan is a very easy IEM to drive, and you shouldn’t have issues running it off of mobile devices. My genres of preference include the following: K-Pop/J-Pop, Country music, EDM, and instrumental scores.
The Sultan arrives in a Nanuk 903 hard-carry case. While I’m not sure how practical that is given I doubt most people want to transport their IEMs around in such a large case, hey, it certainly can’t hurt. Inside you’re greeted by custom foam-cutouts that store the Sultan, as well as a number of accessories. Because what I received was a demo unit, what follows might not be indicative of everything you’ll receive:
- Assortment of foam and silicon tips
- Noble Audio wristbands
- Magnetic carry-case
- Fabric baggie
- Noble 8-core 2-pin cable
The Sultan itself is constructed of a blend of aluminum and acrylic for the faceplate. Despite the more muted aesthetic, the Sultan’s quite the looker; a lot of effort clearly went into fashioning the faceplate and the overall build quality is excellent. It’s also very reflective, and I struggled to get good photos with my amateur setup! If you want something even more fancy, Noble offers a plethora custom faceplates for an upcharge. I had no issues with fit or comfort, although it’s worth mentioning that the Sultan is on the larger side of things.
Frequency response taken off of an IEC-711 coupler. There is a resonance peak at 7kHz; as such, measurements after this point should not be considered accurate. This Sultan review unit exhibits excellent channel-matching.
The overall tonality of the Sultan is something of a W-shape with a strong emphasis on the sub-bass regions. In general, you can expect the Sultan to have a warm, thick presentation.
Bass is characterized by a strong sub-bass shelf that levels off near 1kHz. Although the Sultan’s bass is unmistakably well-textured and presents adequate decay, transient attack leaves something to be desired. The Sultan struggles to articulate quicker, bass-heavy tracks like Illenium & Excision’s “Gold”. Even the 64 Audio Nio, an IEM I would not consider to be particularly clean in its transient attack, easily bests the Sultan here for macro-detail and speed. This sentiment extends to the Sultan’s midrange which is quite thick thanks to the extended bass shelf and dip to the upper-midrange. If not bloated, it’s largely inoffensive, sure, but not much else.
And we haven’t even gotten to my biggest gripe: The Sultan is fatiguing. You might wonder - how? After all, like most poor electret driver implementations, the Sultan rolls off considerably in the upper-treble with little extension to speak of. The culprit, however, lies in the Sultan’s lower-to-mid treble emphasis. While not readily apparent on first listen, this awkward balance presents itself more strongly over extended listening, and in tandem with the Sultan’s poor imaging chops, triggers what I call the “in-a-pit” effect where instruments feel like they’re bearing down on the listener. Really, it’s a bummer that the extra time taken to implement those electret drivers doesn’t seem to have paid off.
Even more so, as a reviewer, I feel compelled to make clear where I stand: To my ears only, the Sultan’s tuning lacks direction. There are little flaws here and there that ultimately detract heavily from what could have otherwise been a more laid back, thick, guilty-pleasure sound. And at the expense of getting ahead of myself, thus follows the title of this review: Sultan of what, exactly? Most of all, I’m left with the impression that the Sultan itself doesn’t know what it wants to be, and a sultan without his subjects isn’t much of a sultan if you ask me.
But I’m not unfair, and here-in lies an opportunity for the Sultan to redeem itself. Let’s talk about coherency. Coherency is something that often goes undiscussed with hybrid IEMs; it’s indicative of the extent to which one can discern separate drivers and the respective frequencies they are producing. Because a hybrid IEM mix-and-matches driver types, perfect coherency is almost impossible to achieve: Incoherency generally presents itself with a mismatch of note textures, or in the time-domain (such as when a dynamic driver lags behind a quicker BA driver). To this effect, I have to admit the Sultan is surprisingly coherent; I never get the impression that it’s “disjoint”.
The problem? This is mostly by virtue of poor resolving capability, in the sense that the Sultan’s blunted transient attack obscures said issues. Like so, the Sultan is heavily circumscribed by its technical chops. It has a “larger-than-life” quality to its notes, which I don’t dislike, but there isn’t sufficient staging for those notes to expand. Imaging and layering-wise, the Sultan is just...average. On Tom Day's "Where Were We," the Sultan struggles with the most basic of passages; the opening bird chirps sound static, sonic-walled, and there's a subsequent lack of ambiance. As the layers progressively stack, the chirps begin smearing, becoming impossible to locate; the Sultan seems to struggle with anything more nuanced than surface-level detail.
This holds even more true of my usual Sawano Hiroyuki test tracks. On “A/Z,” the Sultan fails to capture either the immediacy of the electronic beeps reverberating throughout the stage, or the intensifying hum in the backdrop that precedes the vocalist Mizuki entering. And when she does enter, there is a notable absence of depth considering the mastering has her further back positionally; likewise, the drums behind her are almost all but obscured on the Sultan’s decidedly 2-dimensional stage. I could go on, but I’ll end on this note: Not once did it feel like the Sultan matched my Moondrop B2, an IEM a tenth its price, for technicalities, much less the other flagship IEMs I had on-hand.
The Encore has more of a reference tuning - more mid-bass punch, upper-midrange tilt, and treble presence. My preferences tend to skew more laidback, and indeed, I gravitate toward the Sultan’s tonality. But as much as I dislike the Encore’s 6kHz treble peak, I’ll be the first to admit that it’s the more technically competent IEM. Layering, staging, and resolution all favor Noble’s previous flagship. Go for the Encore if you want a technical performer and don’t mind some BA timbre, and go for the Sultan if you enjoy a warmer, much thicker sound. In a lot of respects, they’re apt foils.
I think this is the tuning that the Sultan was trying to emulate, but unfortunately ended up making a caricature of. The Nio’s bass shelf also doesn’t level off until almost 1kHz; however, it curves more likeably in the sub-bass, and it smacks the poor Sultan with much greater dynamic slam and transient density. Their midranges are both fairly thick, but the Sultan’s lack of resolving capability exacerbates the inherent weaknesses of a thicker midrange. The Nio’s treble is also more laidback, but I’m inclined to say it extends significantly higher. Seriously, unless you really have your heart set on the Sultan, I’d look at the Nio; its blue abalone faceplates aren’t half-bad either.
IEMs like the Sultan are the most difficult for me to review. I do see why the Sultan’s overly-thick sound might appeal to some listeners; however, while the Sultan’s not bad, it’s by no means what I would qualify as “good” either. And the kicker? For the entirety of this sound analysis, I’ve assessed the Sultan to the standards of a much, much, less expensive IEM. Trust me when I say I’d rather not delve into how the Sultan would fare if I held it to flagship standards.
Should you buy a Sultan? Frankly, no, probably not if you care about your sound quality. But on the bright side, the art and craftsmanship that goes into these IEMs is unparalleled. That’s not something I can put a price on, and you’ll need to weigh how much that’s worth to you. I think it’s safe to say Noble Audio has nailed their aesthetics game; conversely, it’s nigh time they hopped on their sound one.
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