Campfire Audio Supermoon Custom In Ear Monitors review

My ears always prick up whenever I hear that a new Campfire Audio IEM (in-ear-monitor) has landed on the market. The Portland, Oregon-based manufacturer is responsible for building some of the most influential and highly regarded earphones in recent years including the famous (or should I say, notorious?) Campfire Audio Andromeda, which rightly remains an industry benchmark for many audiophiles and reviewers. 

Their latest release, however, brings something entirely new to the party. Not only are the $2549 Campfire Audio Supermoon Custom In Ear Monitors interesting by virtue of the fact that they’re a brand-new CIEM (Custom In-Ear Monitor) from a renowned manufacturer, but also because they’re the first Campfire Audio product to feature a “custom” planar magnetic driver. Rather than opting for the tried-and-tested balanced armature or dynamic drivers (or a combination thereof), Campfire has chosen the “Supermoon” to debut their latest driver technology - a single full-range 14mm planar magnetic driver whose diaphragm is a mere 2 microns thin. 

A quick word about Custom In-Ear Monitors

If you’ve landed on this article and you’re not quite sure what a “Custom In-Ear Monitor” (or “CIEM” is), let’s quickly get you up to speed. Whereas most IEMs stay firmly put in your ears with the help of foam or silicone tips that are inserted into your inner ear, the entire shell of a CIEM has been individually contoured to the shape of your inner and outer ear based on impressions that have been taken by an audiologist, scanned, and then provided to the manufacturer to create a one-off pair of CIEMs that can only be ever worn by one person: you!

There’s a reason why you often see your favourite artists wearing CIEMs during live performances - as well as providing an exceptionally snug and perfectly-contoured fit for your ears, CIEMs provide excellent levels of passive noise isolation. Because they can attenuate as much as 30dB of ambient noise, CIEMs allow you to better concentrate on the details in what you’re listening to, for an intimate and uninterrupted performance. 

Campfire Supermoon - design and overview 

I will caveat here that the Supermoon pictured here in this review is a universal sample set.  That is, they haven’t been customised for my ears and are instead fitted with standard removable IEM tips. However, the remainder of the IEM is exactly the same as what you’ll get if you order a pair, and are an (almost) identical sonic match. 

After receiving a scan of your impressions, the Campfire Audio team will then create the shell of each IEM using their “Solid Body” 3D-printing process, which is then hand-crafted into the seamless dark blue finish (so dark that you’ll think it’s actually black at first) which feels both reassuringly solid, and comfortable. Aside from the nozzle where the sound comes out, the dark shells are seamless - the only “gap” is reserved for the polished stainless steel inserts which house the driver configuration. In fact, Campfire explains that the only moving part in the entire Supermoon structure is the driver itself. 

Two different fits can be ordered when getting your custom Supermoon created - “audiophile” and “artist”, which Campfire describes as follows:

Audiophile Fit offers a shallow seal depth. We've trimmed and optimised the fit, removing the unnecessary length of traditional in-ear monitors designed for the stage. This fit design is exceptionally comfortable and easy to enjoy wearing. This is an excellent fit style for everyday use, from a daily work commute to a studio.

Artist Fit offers a more traditional seal depth to ensure the necessary sonic isolation and added security you need for demanding on-stage performances. This fit style is excellent for the professional musician, extending into the ear canal for an optimal seal.

I can’t comment on either of these fits with this pair being a universal sample and all, but if I were ordering a new pair of Supermoon (and there’s a good chance I might!) I’d probably opt for the former. I can’t see my stage career kicking off anytime soon, so I’d be using them for straight-up listening pleasure. 

The Supermoon is equipped with Campfire’s standard cable connection choice - the tried and tested MMCX, which ought to give you access to plenty of aftermarket options, although the stock “Smoky Litz” 3.5mm single-ended cable that’s shipped with the Supermoon is lightweight, not prone to tangling nor microphonics, and feels great. Campfire also manufactures a range of excellent “upgrade” cables made of various lengths, materials and terminations, so if you plan on plugging your new custom Supermoons into a balanced source you may want to tick this box when ordering a pair - and I think you may want to, as I’ll go on to explain shortly. 

Campfire Supermoon - key product specifications

Driver units

Custom Planar Driver 2 micron diaphragm


94 dB @ 54.0 mVrms


15.5 Ohms @ 1kHz

Frequency Response

5Hz - 20kHz

Earphone Connector

Beryllium copper MMCX


Campfire Supermoon - packaging and accessories

Full marks here for an excellent unboxing and packaging experience with the Supermoon - opening it up gives you the serious impression that you’re dealing with a premium, quality product, and Campfire has included a nice range of accessories that’ll make your new custom Supermoon a treat to live with as your everyday listening partner. 

Inside the appropriately “stellar”-looking box you’re presented with the following:

  • A black leather zip-up carrying case 
  • A Campfire Audio “button” pin
  • An IEM cleaning tool 
  • A mesh carrying pouch
  • A smaller mesh pouch with divided sections to house each IEM shell in to avoid them bumping/scratching each other
  • A small polishing cloth to help keep those dark shells nice and shiny!

Listening to the Campfire Supermoon

It can be equal parts scepticism and anticipation when listening to a “first-generation” product - that is, the first Campfire Audio product to receive their new planar magnetic driver. However, it doesn’t take long at all to realise that there’s something very special about how the Supermoon sounds - it’s one highly adept and technically-brilliant IEM that shares many of the traits familiar to planar-equipped headphones and IEMs, namely an incredibly snappy handling of musical transients and laser-focused attack and decay. In fact, I’ll go out on a limb and say that the sheer speed and precision of the Supermoon makes it probably the most technically-proficient Campfire Audio offering to date - this 14mm planar driver really is quite remarkable in terms of what it can muster. 

As we all know, technical abilities don’t count for squat if they aren’t matched with a decent tuning and those other je ne sais quoi intangibles that simply make you want to keep on listening and enjoy album after album. Fortunately, the Supermoon has been blessed with a unique, and yet addictive voicing that definitely gives them their own place within the Campfire Audio lineup. While it’s certainly not a “neutral” tuning by any stretch of the imagination, the Supermoon has an extremely coherent and well-sorted sound throughout its frequency response that is probably better described as linear. I haven’t seen any measurements of the Supermoon as yet, but to my ears, it has a mild “U-shaped” tuning with a strong sub-bass focus, a mildly restrained and yet well-textured mid-range, and a well-extended treble with terrific definition and detail that never gets overly strident nor fatiguing. 

“Planar bass” is a term that you may have come across when reading about the different performance attributes of headphone driver technology, and the Supermoon is an absolutely textbook example of some of the best bass I’ve heard in an IEM thus far. In fact, the Supermoon’s bass is quite possibly its standout feature - it’s spritely, super well-extended, and hits hard. If you’re used to the softer thump of the sort of mid-bass focus that your standard dynamic driver IEM delivers then it may take a track or two to get used to, but for me, there’s no going back once you’re accustomed to the impossibly deep-reaching slam of the Supermoon’s bass which is entirely linear and doesn’t ever mess with the mid-range. When the bass guitar and drums come in at 1:13 on the title track from Tool’s Lateralus you can’t help but go “phwoooaar…” (a highly technical term, I know). 

I do find with some planar-equipped headphones that they leave me feeling a little lacking when it comes to a sense of dynamics - especially in the way they present the lowest octave or two. Despite measuring ruler-flat right down to 15hZ, some planars make me feel like they’re describing bass notes rather than actually making me feel them. The impressive thing about the Supermoon is the way that it manages to combine the slam and shove of a dynamic driver with the reach and speed of a planar driver, and that’s on full display when recreating the sound of well-recorded drums, in particular. Take for instance Opeth’s Beneath the Mire, where the snap of the snare and the left>right roll on the toms in the opening bar give you all the visceral feel of a live drum performance…and then you feel absolutely pummelled by the fast kick-drum at the 0:45 mark. 

While the Supermoon’s mid-range isn’t especially forward-sounding I wouldn’t go so far as to say that it’s recessed - it has a more airy and delicate quality which adds to an absolutely terrific sense of space and soundstage. Thom Yorke’s vocals in The Numbers definitely convey all the texture and analogue-ness that I’m used to hearing in that track, but he sounds a half step further away from the mic than I’m used to with the Campfire Andromeda. However, it’s the scale and grandeur of the string section (especially at that part of the song at 3:30) that is most striking - there’s detail and resolution in abundance, but most of all you get the sense that the Supermoon sounds far bigger than a tiny IEM has any right to. 

I do prefer a little extra crispness in the treble department, and the Supermoon’s highest octave lies smack-back in my “sweet spot” for treble. It’s definitely not a “laid back” IEM when it comes to serving up treble detail, but rather lays everything out on the table with a great sense of air around individual notes which are adroitly separated from one another with stunning clarity. The reverbed vocals, synth, cymbals and finger clicks (listen closely, they’re there) in Tame Impala’s The Less I Know the Better are not only laid out on a lovely wide platter but they’re also separated with varying height as well. It’s hard to believe that there’s only one driver taking care of business inside the Supermoon, but the way that it can dispatch snappy notes with super-fast leading and trailing edges of notes while at the same time displaying a perfect sense of airy decay with lingering, echoey notes is super impressive. 

Campfire Supermoon - Powering and Pairing 

The Supermoon’s 94dB sensitivity is on the low side, as far as IEMs go, and I found that it does need a little more juice than you’d expect to get it going. The interesting thing about the Supermoon is that it actually rewards you with better performance the more power that you throw at it, and so I’d recommend that you consider pairing it with an appropriately-powerful portable (or desktop!) source to get the best out of it. 

The recently-released iFi audio GO bar Ultraportable DAC & Headphone Amplifier, with nearly half a watt of power on tap has more than enough juice to enjoy a properly spirited and dynamic performance of Faith No More Evidence, but I found that holding both buttons down to turn on the GO bar’s “Turbo Mode” added an extra dose of bass guitar heft and a little more space and air up top for a thoroughly impressive all-round listening experience. 

Switching between two different DAPs in the form of the Astell&Kern A&futura SE200 Digital Audio Player and the Astell&Kern KANN MAX Digital Audio Player, I was surprised by how much more overall aggressiveness and slam the Supermoon displayed when playing with the latter. The KANN MAX has a maximum output of 15v (versus the 4v of the SE200) through its balanced output, and it really did show the willingness of the Supermoon to eat up that extra voltage and create a bassier and richer overall tone versus the more linear sound of the SE200. “High” gain mode felt like the right mode to use the Supermoon with on the KANN MAX, and I can highly recommend it as a portable companion should you decide to customise yourself a pair of Supermoon (take a peek at my Astell&Kern KANN MAX Digital Audio Player Review if you’d like to know more about this DAP). 

Being not particularly sensitive, the Supermoon is actually very well suited for listening with a high-quality, discrete desktop amplifier. I had to turn the volume knob on the Burson Audio Funk Headphone & Speaker Amplifier well past 12 o’clock in high gain before I got any sort of audible hiss out of the Supermoon, and the Funk is a 3 Watt Class-A desktop amplifier! With the Funk at 8 o’clock in high gain, it rewarded me with an added dose of slam and soundstage from Living Colour’s Love Rears Up Its Ugly Head - when I wasn’t out on the go you can bet that I chose the Funk over a DAP every time I wanted to enjoy some desktop listening with the Supermoon. 

Final thoughts

Campfire Audio seems to be onto a winner with their new 14mm planar driver - forgoing multiple drivers and the associated crossovers seems to have done no harm whatsoever, and in fact, the Supermoon benefits from a linear, coherent tuning with simply outstanding technicalities as a result. I can’t wait to see what they do with this new driver down the track, but for now, they’ve hit it out of the park with its first outing in the Supermoon. 

If you’re looking to get yourself a new pair of CIEMs, or a pair of “regular” IEMs for that matter I’d recommend giving your nearest Addicted To Audio store a buzz to see if you can spend some time listening to a universal pair of Supermoons to get a sense of their unique sound signature that definitely needs to be heard to understand just what they can do. Grab yourself a quality DAP or headphone amplifier, and you’ll be over the moon. 

Campfire audioCiemCustom in ear monitors