Campfire Audio Solaris 2020 in-ear monitors

“Designed and hand-assembled in Portland, Oregon” is not something one commonly sees with regard to audio equipment. But that’s the case for the Campfire Audio Solaris 2020 in-ear monitors. Campfire Audio specialises almost exclusively in IEMs, with around fifteen different models on offer, priced from a little over $400 up to nearly $3,000. The Solaris 2020 IEMs tend towards the higher end of that range.


  • Quality in-ear monitors
  • Drivers: 2 x balanced armature for treble, 1 x balanced armature for midrange, 1 x 10mm dynamic for bass
  • Connects to 1.2 metre cable with MMCX, so cable can be changed
  • 11 types and sizes of tips, including three of memory foam
  • First class tonal balance
  • Fine detail
  • Amazingly sensitive, possibly 119dB for 1mW at 1kHz (subject to the correctness of my calculations, but unusually sensitive nonetheless), and able to be driven by low powered sources
  • Price: $2,449
  • Available here.

More detail about the Campfire Audio Solaris 2020 IEMs

Apparently these earphones are built upon the legacy of earlier Solaris models, but with a smaller body size. They may be smaller, but are still fairly large for IEMs. The buds can have the cable replaced should it fail, or should you just want to upgrade it, because they connect via industry standard MMCX connections. As it happens, I’m presently listening through them to a quality portable audio player in balanced mode using a third-party cable. That was principally because I wanted to see if the cable worked.

Of course I did my proper listening using the included 1.2 metre “Super Smoky” Litz cable, which is made using silver-plated copper Litz wire. The cable construction features the currently popular “twisted” look. (Incidentally, I preferred the sound with the included single-ended cable than I did with the balanced cable. But how can you tell whether that was because of the cable or the different outputs on the music player?)

Campfire Audio Solaris 2020 contents

Those buds, disconnected from the wires, weigh 7.3 grams each. They’d probably remain secure in your ears even if they were wireless. But the included cable has integrated ear hooks, so they were very well supported.

Inside, these are three-way, four driver devices. A pair of balanced armature drivers provide treble. A larger balanced armature driver provides midrange. And a 10mm dynamic driver delivers bass.

Finish and extras

The finish uses PVD surface coating. I think the bodies of the earphones are some kind of plastic, but this finish leaves them looking pretty damned fine indeed. (Is good plastic a good construction material for earphones? Well, Camp Audio’s cheaper, and rather famous, Andromeda 2020 earphones use machined aluminium, so I guess Camp Audio reckons the construction material is okay. For me, it’s the results that count.)

The Campfire Audio Solaris 2020 IEMs come with several accessories:

  • A rather stylish sustainable cork zip case;
  • Three small mesh bags, two spaces in each, for carrying extras, such as;
  • Ten sets of ear tips in addition to the pair already installed on the earpieces – three of them are memory foam or, as Campfire Audio labels them, “Marshmallow” tips.
  • A “cleaning tool”, which is a small plastic brush with a wire loop on the other end for dragging whatever deposits your ears may leave out of the earpieces.
Campfire Audio Solaris 2020 - contents of package


    I do wish everyone would adopt a single standard for specifying earphone and headphone sensitivity. Most brands use a dB SPL level for 1 milliwatt input at a specified frequency, typically 1kHz. Campfire Audio specifies the sensitivity of the Solaris 2020 IEMs at 94dBSPL at 1kHz for … 6.54 millivolts RMS input. Why 6.54 millivolts?

    Ah, I see! The Campfire Audio Andromeda 2020 earphones have a sensitivity of 94dBSPL at 1kHz for 7.01mVrms input. So the company does things in reverse, telling you what voltage you need for a given output level, instead of what output level a standard input delivers.

    Time to pull out the calculator and convert. First, they seemed to me to sound like they had a sensitivity significantly higher than my other eargear. So let’s work it out: 6.54 millivolts into a 15.5 ohm load – that’s the rated impedance at 1kHz of these earphones – is 0.0028mW. Now, 1mW is 25.6dB more than 0.0028mW. So that would put the sensitivity of these IEMs at 94 + 25 (say) = 119dB for 1mW input.

    Okay, in all honesty I was going to scoff at that … leaving just a small out in case I’d somehow messed up the conversion. But, really, 119dB for 1mW of input? High efficiency earphones are sometimes a little above 105dB. Still, googling around shows that there are earphones this sensitive. And that great care should be taken with them because it’s so easy to accidentally dump dangerously high levels of sound into your ears.

    Comparing levels

    Now let’s compare briefly with some other IEMs which are not ultra-sensitive. The Sennheiser IE 300 earphones, which will be available within weeks, use a different non-standard sensitivity measure, but I was able to convert it into the standard at 106dB for 1mW.

    Campfire Audio Solaris 2020

    I’d been listening to some Eagles at a fairly high level using a high-resolution portable audio player with the Solaris 2020 IEMS. I paused playback, unplugged the Campfire Audio IEMs from both the player and my ears, plugged the Sennheiser IE 300 IEMs into both, and hit play. And there was the music playing away, very, very quietly. I had to wind up the player at lot to bring it to the same level. Suddenly that 119dB for a milliwatt I’d calculated didn’t seem too far off.

    Well, how about a source more mundane? I grabbed my iPhone 8 and plugged a standard Apple analogue audio adaptor into its Lightning port, the Campfire Audio Solaris 2020 earphones into that and fired up TIDAL. And then frantically started stabbing at the down-volume key on the phone because the music was ridiculously loud. (But still clean, undistorted.)

    You know, I’m starting to think that 119dBSPL level for 1mW might actually be right.

    And if you want earphones that have effectively unlimited headroom to use with your iPhone and its dongle, believe me these will not disappoint.


    Designing headphones is hard, and it’s even harder with in-ear monitors. IEMs eliminate all environmental impacts on the sound. The sound is being injected directly into your ear canals, with no mediation even by the shape of your ears, let alone the listening room or whatever. If IEMs delivered the sound with clinical perfection in tonal balance, it would sound simply terrible. It’s the art of the designer to try to tailor the sound so that, tonally at least, it matches what a typical person would experience from loudspeakers.

    But over the years I’ve heard some horrible in-ear gear – more commonly Bluetooth earbuds rather than quality IEMs. Never having used Campfire Audio before, I had no idea how this would go.

    Campfire Audio Solaris 2020 - it's as though it's gift wrapped

    Happily, I fell in love with the sound of the Campfire Audio Solaris 2020 in-ear monitors instantly.

    On Billie Eilish’s “Bury a Friend”, the deepest bass was a little recessed, but everything else was simply brilliant. Her voice had a real immediacy in my ears, and every bit of detail in it was revealed. Because I really enjoy the bass on this recording, I had the level up a little higher than I probably ought to have, but the earphones remained poised and clean. These earphones separated her main vocals from her self-accompaniment better, I think, than just about any other gear I’ve used. I’ll be returning to this track, I think, for other gear, now that I’ve got a kind of benchmark. And even though I would have preferred just a touch higher level in the bass, the powerful bass blasts which act as musical exclamation marks in the rather depressing “Listen before I go” were controlled and solid.

    Changing genres

    Quality jazz recordings were gorgeous. For example, playing right now is “The High Line” from the Alister Spence Trio’s 2003 album Flux. The drum kit is full and superbly dynamic. The cymbals bite without going to excess, while the bass line is clean and easily followed. The kick is solid I could almost feel it, rather than just hear it.

    Laura Marling’s opening track on Once I was an Eagle had her close-miked sibilance in proper balance, neither hidden nor overdone. The layered acoustic instrumentation was nicely handled, with the percussion rendered particularly finely.

    As I was flicking through the half a terabyte of tracks on my portable music player, I happened upon Eagles’ “Hotel California”, something I haven’t listened to for years. This is a 24-bit, 192kHz version that made its way into my collection on DVD Audio. On some equipment this track can be diminished by sounding rather thin. There was no such problem with that using the Campfire Audio Solaris 2020 earphones. The sound was really quite lush with a firm solidity that renewed my interest in the song.

    I used these earphones for quite a while – and, mind you, without any actual running in – over quite the range of jazz, classical and modern music, and I did not find a single weakness. Well, sometimes I would have liked perhaps 3dB more in the deep bass.


    As for long term listening, Campfire Audio says that its “tuned acoustic expansion chamber technology allows us to deliver extended high frequencies without sibilance or fatigue”. I have to agree. Listening was a totally fatigue-free experience.

    On a descending sine wave test – the tone goes from 100 hertz down to 10 hertz over thirty seconds, there was still a solid, audible tone down to 20 hertz, although of course by then the physical movement of the 10mm bass driver against its suspension was also audible. Of course, that’s never audible with actual program content.

    I did not experiment with the many tips provided, but just kept the memory-foam ones on with which they had been delivered. I like these. You just squeeze the foam in, pop the tips into your ears and wait a moment while the foam expands again, seating the buds firmly in your ears and providing an excellent acoustic seal. That seal is the key to the best bass.

    One measurement

    Are the Campfire Audio Solaris 2020 IEMs suitable for use with devices with a high output impedance? I ran a measurement which captures the level of the signal being fed into them via a 460-ohm load, which is the all-too-common but worst-case environment in which these earphones may find themselves.

    Despite the complexity of the driver arrangement, the output was surprisingly smooth, keeping all frequencies within a 1.5dB envelope:

    Input signal variation with 460 ohms inline resistance for Campfire Audio Solaris 2020 IEMs


    One final note: opening up the Campfire Audio Solaris 2020 earphones was a bit like attending a well-heeled party for someone who has provided a reciprocal gift. The cardboard container was golden and glittery. It was clear – the complexity made that obvious, not any sloppiness – that the final package had been put together by workers in Oregon, with various tips placed in two of the included pouches. The presentation was very attractive. To the point, I’d be confident giving these as a gift to someone who appreciates fine audio.

    That someone, though, would have to be very special to me given the $2,099 cost.