FatFeq Maestro SE: Lord of the Bass

Sound impressions

This section covers my general assessment of MSE’s tonal and technical traits. Check out the next section for specific track notes in relation to these impressions, and also how MSE compares to other IEMs. 

I’ve been listening to MSE for the better part of a month, getting to know its characteristics and quirks in that time. Most of my listening has been with iBasso’s DX300 MAX, mainly to be sure that I was giving MSE enough power. I haven’t limited myself to specific test tracks either, listening to new releases and old favourites in equal measure. 


I hear MSE to have a fairly balanced but fun U-shaped tonality. Before everyone goes crazy and starts pointing frantically at the sub-bass ski slope on the graph, let me explain. 

The genius of FatFreq’s tuning is how perfectly controlled they’ve made the bass response in relation to the rest of the frequency range. I’m not sure if they did it using a specific dynamic bass driver or with some sort of voodoo magic, but to my ears MSE has some of the most nuanced, precise and, ok, powerful bass of any IEM I’ve heard at any price point

But, as the saying goes, with great power comes great responsibility, and as much as MSE can slam the fillings out of your lower molars, it does so with the delicacy of a surgical instrument rather than a sledgehammer. You see, most of the bass energy in the fat-bottomed graph is contained below 200Hz, in other words, below the fundamental midbass frequencies, and it only slopes upwards into the sub-bass frequencies that are usually felt more than heard.

Now I’m not sure about your library, but I generally don’t come across too many tracks with copious amounts of sub-bass. In fact, other than some heavy-handed EDM and RnB music that I typically don’t listen to very often, sub-bass is mostly used as an accent, to give the music some weight and contrast rather than defining the shape of the track itself. 

That said, even those tracks that rely on sub-bass for shock and awe, like James Blake’s Limit to Your Love, are buttery smooth down low, with rumble that’s as tight and controlled as it is visceral. By the way, if you haven’t heard this song, check out the test tracks section – it’s an experience!

Coming back to the tuning, both the nature of the bass boost, and the sheer quality of the drivers and acoustics used to pull it off, means you’re getting all the benefit of a life-size subwoofer in your ear without the boom and bloom of a bloated, slow or flabby midbass. It’s often midbass elevation – the so-called midbass hump – that ‘colours’ the sound with bass, bleeding into the lower mids (and sometimes even beyond), and warming up the sound regardless of the music played. 

MSE doesn’t suffer from this bloat. While it has above-neutral midbass, it comes in at a much lower amplitude than the sub-bass, and does so in a linear downward trajectory that keeps the bass fundamentals from veiling any part of the midrange – most of the time. It also means that MSE doesn’t sound anywhere near as warm as an IEM like FiR’s Xe6, with its bold midbass and lower-mid bump – and so for most music, the bass only appears when called for, and doesn’t overtly colour the music. 

I say most of the time because MSE pushes the bass and treble notes forward, or at least above its almost flatly-neutral midrange tuning, which means instruments are generally played forward in the mix, in line with or slightly ahead of the vocals (hence the U-shaped tonality). You could argue that some bass-heavy tracks swing the slope from U to L, but that’s a rarity, and on the whole, I find MSE’s midrange clear, clean and quite transparent. 

Midrange instrument timbre is excellent, with everything from oboes to violins sounding very natural and lifelike to my ears. Piano keys are also very well-articulated, not the easiest trick for an IEM to pull off but one which MSE does with aplomb. As such, I find MSE to be delightful with instrumental music, more so than with vocals.

Because sub-bass frequencies don’t dominate – again, speaking generally, since there are exceptions – vocals can swing from forward to slightly recessed, depending on the mix. Mostly they’re just neutral, especially male vocals, but I find MSE’s female vocal quality unpredictable. 

That comes down to MSE’s design as much as it does its treble tuning, the two of which seem to go hand-in-hand. Initially, I heard some irritating peaks in certain female vocal tracks (most likely centred around the 8KHz peak on the graph), and put that down to lack of burn-in on my part. When the peaks persisted, I started experimenting with tips, and discovered that the peaks all but disappear the deeper the nozzles are inserted. 

Since I tend to start off wearing most IEMs with a shallow fit for comfort, I did the same with MSE. Only when I started wearing them deeper did the consistency of vocal quality improve. For some reason, MSE’s tuning picks apart poorly-recoded female vocals. They can sound grainy with the wrong tips, and also change their character depending on the source and cables used. 

As such, I’d say female vocals aren’t MSE’s strong suit, but that comes with a caveat: worn as intended, and with good quality recordings, MSE’s vocals are as good as any I’ve heard with other IEMs. Tonally they’re not as full or organic as they are with IEM’s like FiR’s Rn6 or HiBy’s Zeta, but neither are they too thin or anemic. 

Aside from influencing vocal anomalies, MSE’s treble is actually quite linear, smooth and well extended, with plenty of sparkle and an almost complete lack of sibilance (short of the occasional and explainable examples I outlined above). 

It’s not the airiest treble presentation I’ve heard, despite the quad e-stats, but I wouldn’t say MSE lacks air, at least not for my taste. In fact, I find the downward upper-treble slope makes for very comfortable listening, but if you’re someone who favours boosted upper treble for maximum technical performance, staging and instrument separation, especially with electronic music, you might find it slightly lacking in this regard. 

Overall, I find MSE’s tonality strikes an excellent balance with the potential for boldness when called for. With certain music, it can be intoxicatingly bassy, punchy and dynamic, with basslines that mimic the experience of a live performance or movie theatre. With most music, however, its character is more evenhanded, with an open, clear and smooth presentation that’s as inoffensive as it is engaging.


Once you’re nearing the $2,000 price point you expect an IEM that ticks just about every high-end technical performance checkbox, and MSE doesn’t disappoint. With its fun tuning and innate ability to put a big smile on any basshead’s face though, it’s never going to be an analytical all-BA technical monster.

Staging is generous, though not super wide or cavernous. I’m still getting a 3D, almost holographic sense of stage, with sounds coming at me from around and above my head in an almost conical sphere, so it’s definitely not closed in or intimate by any measure. 

Imaging is precise, with a nicely-centered vocals and hard-panned stereo separation. Because it’s not thick or warm, and also harder to drive than most IEMs, background noise is a non-issue, and the noise floor with most music is nonexistent. This helps with staging, but also layering and separation of instruments and vocals, which is very good. As a result, MSE never sounds congested, even with fairly complex recordings. 

Resolution is high, roughly at the same level as Rn6 and Z1R, which is to say, mostly excellent. Just don’t expect an analytical microscope where every high-frequency flick and flutter is rendered in crisp three-dimensional detail and you’ll be fine. For music, you’re getting all the information you need, presented in a lifelike and vivid manner, just not shoved in your face like some IEMs are wont to do. 

MSE is also quite dynamic, again maybe not quite as dynamic as Z1R or even Rn6, but not far off. I’m not a stickler for wild dynamic swings, and in fact prefer it when I don’t have to constantly adjust the volume to accommodate softer and louder passages, and while it’s definitely a lively sound at times, it’s not bombastically dynamic like an Xe6.

Overall, there’s nothing in MSE’s technical performance that I could nitpick as a flaw, even with its premium price tag. If you’re looking for a purely neutral high-performance monitor to analyse every nuance of your music from three different angles, this obviously isn’t it. But if you want a dynamic, spacious and resolving IEM that’s fun and refined in equal measure, you’ll find lots to like in MSE.    

Continue to track notes and select comparisons…



Picture of Guy Lerner

Guy Lerner

An avid photographer and writer 'in real life', Guy's passion for music and technology created the perfect storm for his love of portable audio. When he's not playing with the latest and greatest head-fi gear, he prefers to spend time away from the hobby with his two (almost) grown kids and wife in the breathtaking city of Cape Town, and traveling around his native South Africa.


Leave a Reply

Your email address will not be published. Required fields are marked *

Recent posts