FiR Audio Xe6: The Great Frontier

Select comparisons

Sony IER-Z1R. Sony’s flagship is my ‘reference’ IEM, even though it’s far from what most consider reference sound. Xe6 is easily its equal, but in my opinion, not its rival. 

I hear Xe6 and Z1R to have very different bass profiles, Z1R leading with a deep, liquid sub-bass and linear midbass, Xe6 the reverse, with a sub-bass supportive of an elevated midbass. Both have bass quality and texture that exceeds just about any other IEM I’ve heard, including Empire Ears’ bass champions. But, where Z1R’s bass is more even-keeled and balanced in the overall signature, Xe6 is always bass-first. 

Midrange differs too. Xe6 has fuller mids, especially vocals, that are warmer than Z1R’s more neutral presentation. I don’t hear Z1R mids as recessed, though some do, and depending on the bass levels in the music, the same can be said of Xe6. Most of the time, however, both IEMs have some of the better mids I’ve heard, Xe6 being a touch more resolving, Z1R a touch more textured. 

Z1R has more of a lower treble emphasis than Xe6, which doesn’t have any specific treble emphasis other than possibly a boost of air up top. Xe6 treble is smoother, silkier and more rounded, while Z1R is more incisive, detailed and sparkly. Both have superb treble quality, and I don’t really have a preference between them, enjoying both in equal measure.

Technically Xe6 is a touch more resolving, but Z1R casts a bigger, more cavernous stage, and its imaging and separation are at least on par. Both are very dynamic, but Xe6 even more so. Neither IEM loses too many points on technical performance, so the differences really come down to tuning and, for some, comfort and ergonomics. 

Z1R is notoriously wonky in the ear for many people, while Xe6’s smaller, lighter universal shell should be a better fit for most ears. It’s not for mine, however, so an audition is really the best way to know which works best for you.  

Unique Melody ‘Multiverse’ Mentor. I haven’t spent nearly as much time with Unique Melody’s co-flagship, but the time I did spend with it made it clear for me that it’s doesn’t have the same level of engagement for me as Xe6.

These two IEMs couldn’t be more different. Xe6 is bold and dynamic, with an inviting tonality that swings wildly between extremes. Mentor is more balanced, but also livelier and more energetic up top that gives it an oddly disjointed personality. Where Xe6 is rich, organic, and sometimes a little ‘loose’, Mentor is the definition of technical precision. Xe6 infuses music with a sense of tonal wonder; Mentor wows you with technical trickery. 

For me, Mentor is not an IEM for bass lovers. For all its technical prowess, Mentor’s bass leaves me cold and unsatisfied. It’s the fly in the ointment of an otherwise impressive IEM, which becomes even more apparent when comparing it to the bass masterpiece that is Xe6. I know that’s not going to be a shared opinion by some, who take no issue with Mentor’s sub-bass rolloff and ‘balanced’ BA bass delivery as a whole. But for anyone who needs to feel the kick of a drum in a live performance, Mentor just isn’t the right tool for that job. 

Nitpicking other differences between the two, Xe6 is by far the better-made IEM, with Mentor’s dullish exterior and structural ‘imperfections’ not quite up to the quality of Xe6’s pristine all-metal design.

Campfire Audio Supermoon. I’m only comparing Xe6 to Supermoon because I happen to have both on hand. 

Supermoon is a custom IEM (though a universal version exists), so from a fit perspective it’s no contest in favour of Supermoon (though Xe6 is also available as a custom). Technically, Supermoon easily trades blows with Xe6 in all but dynamic contrast, which may or may not be as important to the music you listen to (and if it’s not, bonus points to Supermoon).

Where Xe6 overtakes Supermoon, in my opinion, is its tonality and timbre. Supermoon is colder and more ‘digital’ compared to Xe6’s warmer, more organic and natural tone. Supermoon also suffers from thinner mids, and the occasional metallic timbre in the upper-mid/treble region, whereas Xe6 is about as far away from metallic as you get. 

None of this is to say that Xe6 is clearly the right choice for you over Supermoon. If you’re familiar with planar timbre and dynamics, you won’t have any issues adapting to Supermoon’s outstanding IEM-sized presentations of both. If you like your music superfast, resolving and clear, with world-class sub-bass to boot, Supermoon outdoes Xe6 there too. 

Both IEMs are their own type of ‘crazy’ in many ways, and will appeal to those that don’t always want to play their music safe. In a way they’re kindred spirits, but definitely cut from very different cloths. 

Continue to closing thoughts…



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.


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