Campfire Audio Solaris – sound like the sun

Acknowledgement

The Solaris were very kindly provided by Ken Ball at Campfire Audio for the purposes of writing a full review. I paid nothing for these, and there is no obligation to or input from Campfire Audio with regards to the content of the review. Allegations was (politely) asked for was a few brief impressions to be posted as soon as possible (which were outlined in a previous post) and a more thorough review once I’d got to grips with the sound. Unfortunately, due to some personal circumstances and just a healthy dose of life in general getting in the way, it has taken a lot longer than I thought to publish the follow up review – while this has given me a few months to get fully to grips with all the nuances this hybrid beast has to offer, I’d like to extend heartfelt apologies to Ken and his team for the delay.

Ratings

Introduction, build and ergonomics

Campfire Audio are a company who need pretty much no introduction these days, if you are a follower of the IEM (in ear monitor) scene on sites like Head-Fi or the other audio forums out there. They have been making waves for the last three or so years with a series of IEMs that are almost universally well-received, building a reputation as a manufacturer with a strong emphasis on musicality and value for money (if such a thing exists in the world of $1000 headphones!).

The Solaris is the latest evolution of the Campfire Audio line, a four-driver hybrid that brings together all of their current design and tuning knowhow into their defacto flagship model, sitting on top of their universal range at $1499. This brings together their ADLC dynamic driver found in their DD flagship the Atlas, the Polarity DD tuning chamber technology designed for their Polaris and Atlas models and the now-ubiquitous TAEC (Tuned Acoustic Expansion Chamber) technology used in the higher end BA models. This is all married together with a single custom designed crossover, with the DD firing across the full range, one back-vented balanced armature to pick up the midrange and a pair of TAEC BAs taking care of the treble.

All of this is packed into a shell which adopts a more “pseudo-custom” shape than previous models, swapping the more angular edges of the Andromeda and Atlas for a smoother and more textured curve, leading down to an angular nozzle with a steel “grating” to keep out dirt and debris. It is still unmistakably Campfire, sharing an identical nozzle design with the front assembly of the Atlas. The metalwork on the case is highly detailed, with multiple ridges on the inner surface giving a nice visual sense of texture. It contrasts well with the PVD-deposited (makes a really durable finish) 24k gold plating on the outer surface of the shell, making this a visually striking IEM. The two tone colour scheme works nicely here, looking a little more classy than the blue and black of the Polaris (another hybrid model in the CA range). It is a unique design, and one that won’t be easily mistaken for any other IEM currently on the market, so kudos to Ken and team for coming out with another striking industrial design piece here.

Size wise, this is on the slightly large side, but sits well in the ear and doesn’t feel overly heavy. The ergonomics are actually surprisingly good, considering the size of the shell. The Solaris do stick out a little from my ears, but not nearly as badly as something like the JH Audio Angie (v1), which used to protrude at least a few cm out from each ear-hole when wearing. With foam tips or the correct silicone tip styles (Final E work well for me, as do Spiral Dots), the Solaris sit firmly in the ear, with a stable and comfortable positioning. These aren’t the sort of IEMs that lock in place so tightly you will be running marathons in them, but then again, who does that with $1499 worth of audio gear in their ears?

I’m not a huge fan of the memory wire implementation on the CA cables, but when worn without custom tips, I find the memory wire very useful for additional security, so if you are a fervent hater of all things memory-related when it comes to cables, this may inform your tip choices when wearing the Solaris.

Once correctly seated, the shell feels smooth and light in the ear, allowing for some seriously long listening sessions without generating any hot spots or discomfort in the outer ear. For reference, my ear cavities are only marginally smaller than some of the craters the Mars Rover is currently driving through, so please bear that in mind. Given the smooth lines on the inner face, I can’t see this causing an issue with smaller eared users in terms of comfort. There is no getting away from the fact that the Solaris are a big-shelled in ear monitor, so CA’s latest hybrid may stick out a fair bit further than your other gear if your lugholes are on the more petite side. As with all high end gear in this sort of bracket, it’s always best to try and audition before you buy.

One final note on ergonomics and build should go to the new SuperLitz cable included with this model. It sports the twisted braid of the recent Atlas Silver cabling, but is made of a thicker gauge wiring with multiple different strand sizes internally. This makes it a thicker and more substantial cable than the previous Litz cables on the Andro / Atlas etc, with a heftier feel in the hand. The twisted braiding mean it is still supremely flexible, and has practically no memory after being coiled. The additional weight actually helps the cable sit nicely flat when worn, adding to the premium feel of the whole package. The cable is also very quiet (mainly due to the memory wire), so is a quality addition overall. I was lucky enough to get sent a 4.4mm terminated cable as well as the “stock” 3.5mm termination, so have settled on the 4.4mm for daily use with my gear, using a pigtail adapter to hook it up to my other balanced or single ended sources as needed. With most high-end IEMs there is a tendency for buyers to investigate cable rolling once they have got used to the sound, but having rolled a few of my available cables through the Solaris, I keep coming back to the original SuperLitz as by far the best “fit” both in terms of ergonomics and general SQ, so a cable upgrade is certainly not a requirement for most users here if sonics are your main consideration. Cables are a fairly contentious issue for most anyway, so it is nice to see ALO/Campfire providing something that is already firmly in the “after-market” category in both looks and build as standard.

Unboxing

The Solaris comes in a larger art-card box than the usual Campfire models, keeping the same sort of height but now fully square to accommodate the larger “deluxe” carrying case. Opening the box reveals the now-synonymous Campfire Audio fur-lined leather case, which is upholstered in a brown leather (or leatherette) material, and is approximately twice the size of the previous cases. This moves it from being pocketable in a jeans pocket to more of a jacket-pocket carry if you are intending to take the Solaris out and about, but makes sense to accommodate the larger physical dimensions of the IEM and the thicker SuperLitz cable.

The rest of the loadout is pretty standard Campfire Audio fare, with Final E-type tips, campfire silicon and foam tips, a small CA pin and IEM cleaning brush and an ALO Cable. The cable is a new SuperLitz design, with differing strand sizes and a silver-plated copper composition. The only other unusual addition is a nice Campfire branded drawstring bag with two sections, designed to hold the IEM shells when you are transporting them in order to avoid the metal colliding when in transit. It is a definite improvement on the previous red velvet bags, as the cabling on my Vega actually ended up with some staining from the dye of the bags, so another nice evolution.

Specs

Initial impressions on sound

So, what was my initial impression of these babies straight out of the box? Pretty damn good, is the answer. They undeniably sound like a Campfire Audio product, sharing the musical DNA of the TOTL models that have preceded them, but not sounding exactly like any of them. On first listen, I was actually expecting to hear something like the Atlas with an airier top end, but was actually struck by the richness of the sound rather than a sense of sparkle. The Solaris are described on the Campfire site as thinning the walls between high-end two channel hi-fi and personal audio, and  the Solaris packs a tonality and fullness to the sound that supports that assessment.

Before any 2-channel enthusiasts start reaching for the pitchforks, I’m not suggesting that the Solaris is exactly like strapping two large cabinets to your ears. What it does bring to the sound is a sense of dimensionality that makes it feel more like listening to the sound system in your favourite music venue than from two small in-ear speakers. The sound is big and bold, carrying plenty of bass but with a little less emphasis than the Atlas, and a more engaging midrange. Despite the size of the image in your head, the presentation still feels intimate, pulling vocals forward towards the listener and spreading guitars and other instruments across the stage.

The vocals in particular are impressive, sounding clean but ultra-textured, and feeling more “3D” than flat. I suspect that this is a monitor that will be a top-tier contender in terms of imaging and staging – it is far too early to make that sort of assessment now, but the depth portrayed in the tracks I have listened to so far bode very well. Detail levels are high across the board, but there is an almost vinyl-esque sheen to the music which reminds me of the way the Empire Ears Zeus spits out detail, relying on true resolution rather than treble sharpness to get the sonic information across. These don’t feel like the most overtly detailed IEMs I have ever heard in the TOTL bracket, but again, it’s way too early to really tell, and they certainly don’t feel lacking. They share that smooth detailing that makes the Andromeda such a great in-ear, but take the tone and body and kick it up a gear.

Treble is clean, clear and extended. It sits nicely in balance with the other two frequency ranges, neither too hot or too dull. Anyone who has heard one of the previous TAEC models should know what to expect here.

Overall, the sound is rich and slightly warm, with a serious amount of bass underpinning a musical and resolving upper ranges. Guitar and piano sound crisp and real, and vocals are emotionally engaging. It marries the best aspects of the Andromeda and Atlas together for me, and the synergy makes for something pretty special. This will be less polarising than the Atlas, but it is an evolution of the rich and musical sound that Campfire have been pioneering with the recent Atlas and Cascade models, with some of the OG Andromeda goodness thrown in the mix for good measure. This doesn’t just add more bass to the Andro tuning, and it doesn’t simply air out the Atlas some more – this is a different beast, but I can see why Ken has been so enthusiastic about it. It plays in the TOTL bracket in terms of technical prowess, while sounding just a little different from anything I have heard before. It almost has aspects of the “3D room emulation” from my Audeze Mobius headphones, the sound feels that rounded – it’s an unusual analogy, but one that probably best fits what my ears are hearing – the sound is inside your head, but also all around you.

Update on sound after burn-in

After a solid month of long chunks of burning in and a healthy dose of listening as and when I could plus a few more months of general everyday use, I probably now have at least 500 hrs on this particular set as at time of finishing this review. I have deliberately left the initial “knee jerk” impressions from my first contact with the Solaris in the paragraphs above, to give a contrast on how I heard them initially and where my brain / the drivers have settled in terms of signature and listening experience.

When I was discussing the Solaris with Ken Ball initially, the subject of burn in came up. While I’m personally fairly open minded when it comes to the effect of burn in on audio gear, I know it’s a rather emotive subject in the audiophile community, so thought I’d better elaborate a little on the reasons given why this IEM needs a solid burn in period. Ken has suggested 5 to 6 days of constant use for the Solaris before they reach their full potential. Even listening for 4 hours a day every day, that would take a calendar month. Being the impatient type, I took the slightly easier route of hooking the Solaris up to my mains-attached Shanling M0 and kept it playing 24/7 until it was well past the prescribed number of hours, with a break every day for an hour or so and the occasional listening session to break things up.

So, why the ultra-long break in period? Ken gave the following two reasons:

• The ADLC driver design will loosen up and reach full mechanical excursion potential after 100-150 hours of use
• The dielectric in the crossover will also benefit from the extended break in period

Now, whether you believe or disbelieve the science, to my ears I heard a difference in both staging width and tightness and impact of the bass (which are likely interrelated). I also perceive the quantity of bass slightly differently, which I will go into in more detail below. Whether it is brain-burn, mechanical or electrical improvement or good old fashioned placebo I can’t say for certain, but my recommendation for any future Solaris users is to put the CA recommended number of hours on these IEMs before passing final judgement on the sound. It’s more of a subtle shift than a sonic epiphany, but if your experience is like mine, you’ll be glad you did. To reflect this perceived shift in sound from the Solaris, I have included a second impressions section below, which reflect the overall impressions I now have after an extended period of listening and use.

“Initial” impressions on sound (part 2)

The sound is full and deep, with a sense of balance that evokes the sort of natural neutrality of the Andromeda. Bass is still impactful, but now feels surprisingly restrained given the fact the dynamic driver used in this hybrid is the same as the one producing the ammunition for the bass cannon of the current CA lineup, the Atlas. Ken and co have opted for a more linear and controlled bass tuning here, with the Solaris keeping a tight rein on the overall quantity, but still providing that dash of visceral impact that all good DDs can bring to the party. Sheer volume has been traded for texture and layering, with the Solaris pushing out some serious detailing in the lower end, with extension and texturing to spare. Initially I thought the Solaris was on the bassy side of things, but after more listening I realised I was mistaking the “subwoofer” style tuning of the lower sub-bass for overall bass quantity, which is actually a little less than originally imagined, and barely more than neutral when taken as an overall whole.

Moving up to the mids, vocals still sit prominently in the mix, with a perceived rise in the early kHz to position the singer closer to the eardrum than the back of the stage, but still not quite as far forward as something like the Zeus. This slight emphasis is countered by what I hear to be a slight dip a little further up the frequency range (just after the female vocal ranges usually end), allowing the vocals to stand front and centre without the rest of the midrange instrumentation dominating the soundscape. The presentation here feels intimate but not crowded, bringing the “heart” of the music close to the listener without losing the widescreen sense of scale.

The tonality across the board is superb, with a very organic sound to instruments like piano and acoustic guitar. Notes feel full bodied without sounding thick or gloopy in the ear, bringing sharpness or liquidity as the recording demands. In fact, the transparency is one of the things that really hits you the more you listen to these, with the Solaris staying true to the inherent rawness or warmth of the underlying recording without adding too much of its own flavour to the mix. It is a monitor that has a distinctive tone and colour of its own, but still remains true to the mastering of the music underneath, which is a a rare combination.

The treble is taken care of by the now-famous Campfire Audio TAEC system, made up of a pair of BA drivers and a 3D printed tubeless resonating chamber. Like the rest of the signature, the highs here carry genuine weight, extending high but remaining solid in the ear rather than ephemeral. There is still plenty of air and sparkle in the presentation, but the additional heft from the mids and bass underneath make this less of a spacious and delicate sound than its predecessor the Andromeda. It certainly isn’t smoothed over or blunted in any way, but people looking for a carbon copy of the Andro’s signature top end will be disappointed.

In terms of position, treble holds fairly steady with the midrange, with just a bit of extra push at the topmost extension of the sound. It is crystal clear, and carries some of that indefinable “sparkle” that makes the edge of cymbal notes and other high range detail shimmer just a little in the ear, decaying delicately into nothing. There is a weight to the treble that adds to the unique analogue or vinylesque tonality that this IEM is capable of achieving, giving instruments room to soar but stopping them from becoming truly ethereal or gossamer-thin in the ear, keeping things firmly grounded and substantial. As mentioned, this isn’t a carbon copy of the Andromeda’s highly rated high end. For my personal preferences (thick and smooth treble over crispy and razor-sharp), this is right in the sweet spot – it may leave a few Andro fans wanting a shade more “zing” or shimmer in the upper reaches of their favourite tracks, but I think the treble is tuned just right to complement the rest of the sound ranges – too much would have unbalanced the delicate alchemy of the overall signature so I’m personally glad Ken chose this path.

Bass

Delving into the individual frequency ranges in more detail, the bass on the Solaris is a point of debate among the audiophile community. Some are concerned that the CA hybrid may have toned down the mighty ADLC driver a little too much from its fire and brimstone heyday powering the Atlas to the top of the audiophile basshead tree. Personally, I’m of the opinion that the bass is ideally judged for the rest of the frequency range, neither too little or too much. It has impact and a sense of physicality, hitting with a muscular thud on drum impacts, and giving bass guitar and synth a well rounded presence, if not an overwhelming sense of volume.

“Tommy The Cat” by Primus is a good example of the above, the riotous jazz/rock bass riffing of Les Claypool that underlines the song hitting the eardrums with a genuine fizz as the strings pop and vibrate. The kick drum riff that appears at 0:32 feels so real in the ear that you can practically see the skin of the drum vibrate as it gets hit by the pedal, capturing a crystal clear image in the mind. It is a mixture of power and control that makes the song sound almost primal, without having to blow you away with sheer volume or slam.

Moving on to my more usual bass testers, “Heavy” by Emile Sande is up first. This song leads off with a sub bass synth rumble that persists throughout, and this is present on the Solaris but not massively emphasised, giving more of a tickle than a thrum in the ear. It still has substance and extension, but doesn’t dominate the sound like it can on monitors with more of a sub bass slant.

Similarly, “Heavy” by Linkin Park carries the depth and texture of the (sub)bassline well, but probably not enough to keep a true basshead salivating. There is still physicality to it, bringing a slam that is almost at odds with the quantity. This is almost the inverse of a traditional “BA bass”, delivering only a medium thrum in the ear but maximum physicality and air movement that only comes with a good dynamic driver. That seems in part to account for the “subwoofer effect” that the Solaris so effortlessly conjures up when listening to certain tracks, being able to make them sound like there is a proper 2-channel subwoofer in play, rather than the actual quantity of bass hitting the eardrum. 

Midbass is thicker in volume, and absolutely drips with texture. It feels velvety and thick, coming through just a little north of neutral on most tracks but definitely still sitting more towards balanced than basshead. This is where the real texture in the low end starts to show its face, revealing layer upon layer of bass in your favourite tracks that other monitors may just smooth over. Some of the retrieval is so nuanced that if you stuffed it into a Gucci tuxedo and rolled out onstage at the Oscars, it would probably come home with an award. This thing can legitimately lay claim to being the Daniel Day-Lewis of bass, in my humble opinion, matching its presentation to the material like a sonic chameleon, capable of captivating nuance and occasionally surprising brutality in the same track.

“Get Lucky” by Daft Punk and “California Love” by Dr Dre are dispatched with aplomb, the liquid bassline of the Daft Punk track dropping low as maintaining its infinitely varied shades in the ear. Dre brings an altogether more in your face vibe, the Solaris responding to the additional low end in the mix with a controlled and punchy rendition, with more than enough volume to get the head nodding. There is slightly more weight to the mid bass tones here, carrying more fullness than the surprisingly punchy but lighter sub bass. “Reptile” by Skrillex also comes out surprisingly well, the mix of impact and fullness actually giving the track a fairly prominent low end, with the hammering electro-bass riffs filling the ear nicely. The ADLC driver shows its chops here, keeping all the differing layers of sound cohesive as the track builds, immersing the listener into the dubstep soundscape and the various dynamic shifts as Skrillex bends and twists the sound.

Kicking things up a gear, “Bad Rain” by Slash hits with genuine impact, the simple 4-4 drum beat that drives the intro arriving with punch in the ear. The growling bass guitar that follows feels textured and raw, diffusing out into the soundscape after each hit. The decay is controlled but very organic sounding, lingering just long enough in the background to give that sense of presence without muddying up the next note. Mid bass presence is more towards neutral here, with the bass clearly audible, but leaving more of an impression of texture and physicality than sheer volume.

Rounding the bass section off, “Hello, It’s Me” by Sister Hazel and “The Chain” by Fleetwood Mac are up. The Sister Hazel track practically oozes bass on some monitors, and the Solaris doesn’t disappoint here. The bassline feels lithe and flexible, each note carrying fine texture around each plucked string as it is hit. It doesn’t dominate the low end or completely fill the stage like it can on something like the CA Atlas, keeping a more reserved but still musical approach. The texture of the notes sits somewhere between chalky and liquid, carrying the smoothness of the latter without ever feeling fully “melted” in the ear. It shows control as well as flexibility, sitting in that Goldilocks zone that gives maximum musicality without resorting to overly sloppy or liquid reproduction of notes.

One final thing to note on the Solaris is the potential for EQ in the lower regions. This is the same driver that floods the ear with bass boom when called upon in the Atlas, and with the right electronic stimulation, this IEM can be turned into a serious bass-capable beast. Jacking the low end EQ on my N5IIs or DX200, the Solaris responds in kind with a heavier, much more prominent bass, that adds a layer of warmth to the sound at the expense of some of the crystal clear midrange tuning. It doesn’t distort on anything I’ve tried it on yet, so if you have access to a high quality parametric EQ, this should allow you to add some decent dBs to the bass response without too serious an effect on the overall quality of sound. Personally, I’m happy to leave the bass dials where they are, as any attempts I made to bring in some Atlas style boom took too much away from the delicate balance of the rest of the sound to be worth the additional bass.

Overall, this is bass of the highest quality, with enough presence to keep most people more than happy and top tier texture and layering, along with a real physical impact to give the sound that authentic DD flavour. It’s difficult to see where Campfire could have made too many alterations to this tuning given the context of the other frequencies sitting above, so while it isn’t quite my “preferred” or ideal bass tuning, it is probably the best balanced and most accomplished bass I’ve heard yet (and that includes the Atlas, which sounds a little better for my preferences in the low end but doesn’t quite have the undefinable balance that the Solaris possesses).

Mids

The Solaris midrange is taken care of by an overlap of the ADLC driver powering the bass and the same single midrange BA used in the newer Andromeda S model. It is hands down the best hybrid implementation I’ve heard, with no obvious “seam” or audible crossover point in the bass to midrange transition – in fact, the single crossover in use actually sits between the mids and treble, so it really is a masterfully blended mix of BA and DD together, executed without any loss of coherency to the overall sound.

It is a rich but not overwhelmingly full sound, giving plenty of room for delicacy and dynamics throughout the range. Vocals are the star of the show here, imbued with a soulful timbre that evokes the best high end dynamic driver IEMs like the AKT8IE or RE2000, but carrying the detail and clarity of a top flight BA setup. This isn’t a highly coloured sound, but it does carry a slight warmth and air of “natural neutral” that the non-basshead Campfire models have in common. This is an all-rounder’s take on a midrange, with smoothness and space in equal measure, all sitting on a backdrop of solid micro-detail. This allows the Solaris to be complementary to multiple musical genres without picking any particular favourites.

Starting with the voices, Aaron Lewis’ cover of the Chris Stapleton track “Whiskey And You” captures the velvety richness of the ex-Staind singer’s delivery well, full of darkness and grain. It contrasts against the sweeter and lighter voicing of the backing singers, blending to create a multi layered chorus that is both deep and light at the same time.  Similarly, “And On A Rainy Night” from the recent reinterpretation of the “Soul’s Core” album by Shawn Mullins captures the gruffness in Mullins’ half-sung, half-spoken delivery perfectly, pulling the vocal medium-close to the listener and giving it a texture like fine certificate paper as it pulls the small details in his delivery out. It is a sound that feels grounded and resolutely physical, with an air of stylised authenticity in presentation that captures more than its fair share of emotion en route from driver to ear.

Lining up some Mavis Staples, the veteran soul legend sounds like gravel dipped in butter, her distinctive croaky roar sounding both warm and gruff at the same time on “High Note”. The multi-layered chorus places each individual singer in the gospel choruslines at slightly different points around the soundstage, allowing the brain to track each line individually without losing the musicality of the blend. The Solaris is resolving enough to catch the raspy breathing patters in “Love And Trust” by the same singer, slotting them around the warm and soulful vocal to give a three dimensional feel to the delivery. It isn’t hyper-detailed for its price bracket, but there is enough clarity to make the brain feel like the sound is pure and unadulterated, with no hint of veil to my (admittedly less than golden) ears.

Trying some sibilance testers, Chris Stapleton is up first. Hi version of the simple acoustic country ballad “Whiskey And You” is one of my favourite tracks for late night listening, but it does his raw vocal delivery no favours at all, sounding like it has been mixed in a chainsaw testing facility and mastered with sandpaper on some audio gear. The Solaris cruises through the troublesome vocal sections at around the 3 minute mark with no issues, keeping the sound raw and emotional but relying on natural resolution rather than artificial peaks in the upper mids to retain definition without grating on the eardrums in the process. “My Kind Of Love” by Emile Sande has similar mastering issues, and passes a little less smoothly, still avoiding out and out shrillness but definitely bordering on sharp. This is another track that has been mastered on the surface of the sun, so the heat is inherent in the track itself – the transparency of the Solaris plays nicely with most styles of music, but won’t overly smoothe out or hide poorly recorded tracks, so quality of source file and more importantly quality of recording are definitely factors when choosing your playlists here. If you feed it a bag of broken glass, expect your eardrums to get cut to shreds in the process – there is no sonic smoothing at play here. However, feed it Elvis in his prime and it’s Vegas all the way, baby – thank you very much.

The flipside of the Sande tune, “Starlight” by Slash and Myles Kennedy is a track that has an inherently sharp vocal line and some very dissonant guitar work, but is recorded superbly. The Solaris excels here, sharpening Kennedy’s falsetto to a razor-edged wail, but adding body throughout the notes to keep it sounding solid and silky in the ear rather than unpleasantly brittle or rapier-like. 

ticking with the same track, the intro bars demonstrate the capability of the Solaris to handle guitar-based music, delivering pin-sharp harmonics and a crunchy edge to the electric guitar without sacrificing the natural tone. Guitars sound defined, and carry a sense of weight and solidity to them without sounding too beefy or chunky. This isn’t the thick “wall of sound” style you can get on some mid-centric monitors, but like the bass, carries an aspect of physicality that is slightly at odds with its more neutral / natural leanings in terms of note weight. If the midrange instrumentation were a boxer, it would be a super-middleweight: packing enough size and power to do some proper damage without losing speed or carrying too much weight around the edges. This is a monitor that can chug with the best of them (try out some P.O.D. or Metallica for proof), but it isn’t a specialist in this sort of area.

With more acoustic fare, the Solaris really opens up, with a beautiful organicity of tone (copyright @Deezel77 – Head-Fi / THL) that makes strummed strings feel like they are being played in the same room as the listener. “Champagne High” by Sister Hazel is one of my favourite acoustic rock tracks, a fine blend of regretful vocals, delicate acoustic noodlings and a sweeping rock backbeat. The acoustic guitars sound delicate and real in the ear, blending softly with the heartfelt vocal to give the song a genuine emotional ballast. They sit naturally a little further into the background than the singer, the slight dip in the upper midrange pulling the instruments a little behind the voice, giving the Solaris a more “live on stage” style of presentation with certain tracks. There has been some chat on the usual forums about this “scoop” and how it affects the mids – as mentioned above, I think this is pretty well judged, and gives the Solaris a nice balance across the range without making any of the tracks I usually listen to  feel hollow or absent through the midrange. As always, YMMV, but I don’t think this tuning tweak is a worry, and actually adds to the overall signature Ken was shooting for here.

A lot of the beauty in the Solaris midrange comes from the physical presentation of the notes. The two drivers combine to create notes that feel slightly more rounded and three dimensional than an all-BA setup should deliver, and more defined and articulate than a typical dynamic driver. I’m not talking about the often used term “holographic” (although that will likely surface in the soundstage section of this writeup), just the sense that each instrument has more heft in the ear, almost as if you can sense the angle of the notes as well as the notes themselves.

Female vocals have divided a few listeners on the forums so far, with some listeners of Asian alphabet-pop (J and K) noting a recession in the voices of some artists or an unusual timbre. I personally don’t hear any recession or “suck out” with the vocals of the songs and styles of music I listen to. Artists like Amy Helm are just as up front as they always were on tracks like “Odetta”, her smoky and soulful voice sitting just in front of the instruments rather than alongside or behind them. I tend to prefer female singers who operate in the lower registers like Mavis Staples, so I’m more rock chick than mezzo soprano in my female music tastes, so please bear that in mind. The Amy Helm album actually sounds sublime through these IEMs, with a warm tone and analog feel like the best 70s soul recordings, but still packing some great modern day clarity and recording detail.

“Michigan” from the same album starts with some subtle brushed drums and a little organ work, with some delicate acoustic guitar in the left and right periphery of the soundstage and Helm’s deeply soulful vocals sitting right up front. This sounds solemn and reverent as it builds, sweeping the listener into the chorus where Helm is joined by her backing singers. Each chorus vocal renders separately in the ear without losing the sense of togetherness, allowing you to follow the individual lines if you concentrate but not distracting with detail. The vocal isn’t the cleanest recorded delivery I have in my collection, but the Solaris sounds faithful in reproducing the sound as recorded – despite having a great individual “tone”, this isn’t a monitor that will sugar coat or artificially smooth poor recordings – in fact, I’d suggest it is welcoming, but not overly forgiving with poorly mastered source material. The assumption would be that if you are going to spend the best part of $1500 on an in-ear monitor, you are likely to have a suitably refined source and decent source material, but just putting this out there in case you are looking at pairing these with your Android mobile phone or a collection of 128kbps MP3 from the 90s (each to their own, and all that).

Switching up to some of my favourite rock tracks, Slash is up next. The Solaris handles rock guitar pretty well – it isn’t the crispest monitor out there, but if treads the right sort of line between sharp-edged attack on guitar riffs and a blunter and more full bodied sound. “World On Fire” from the album of the same name kicks off at 100mph, with the guitars feeling solid in the ear, moving nimbly around the quickfire riffs but still carrying some resonating chug in the ear and a satisfying distorted wail.. “Shadow Life” is dealt with the same way, the staccato riff descending into the chorus stopping and starting on a sixpence with excellent control, but still sounding analogue and almost tube-warm in tone, with a solid sense of gravitas and sonic weight. The riffs are supported by the solidity of the lower end, picking up some rounding to the lower harmonic edges from the DD portion of the midrange pairing. This isn’t to the same level of thickness or heft as the original owner of the 10mm DD, with the Atlas possessing a more full-bodied presentation with these sort of tracks. There is still enough depth to make the Solaris sound planted and full, however, with the combination of BA speed and organic and almost tube-like warmth to the tone sounding a little reminiscent of the Angie by JH Audio, with just a splash more presence to the notes.

As mentioned, speed isn’t an issue, with the IEM handling frenetic rockers like “From The Sky” by Tremonti or “Coming Home” by Sons of Apollo just as easily as it chews through my Foy Vance back catalogue. In fact, the mythical PRaT (Pace, Rhythm and Timing) of this IEM is top class, with the Solaris able to capture the uptempo groove of something like “Dubai Blues” by Chickenfoot with all its toe-tapping groove, matching technicality with a swing to the sound that feels musical rather than analytical. This is another side-effect of the overall coherence, with each driver moving with control and speed to give a vice-tight grip on the underlying music tempo, translating well into the ear.

Other midrange instrumentation sounds accurate, with a slight warmth to the tonality but nothing too stylised. Piano rings true to my ear, and strings sound three dimensional and just… right to me. “Kentucky Rain” by Elvis and the Royal Philharmonic has a delicate orchestral backing and a sweeping lower end, and the Solaris deal with both easily. The delicate finger-picked acoustic guitar sounds barely-there it is so light against Elvis’ velvety crooning, the layers of horn and trumpet and gospel chorus building as the song rolls on through its chorus, giving a dynamic swell and recession to the track that feels like a good live performance. The separation and layering abilities of the Solaris also come to the fore here, giving the various instruments a little room to breathe without diffusing through the soundstage, leaving just enough black space around notes to give that authentic feeling of top-tier clarity. The absolute resolution of this IEM in the midrange probably won’t bother something like the Jomo Flamenco or Zeus-XR, but with the tuning choice Campfire have gone for, it doesn’t need to. The pinpoint image and top notch separation make this almost an irrelevance, bringing out nuance by clearing the space around each little micro-sound rather than turning up the resolution to make it stand out.

To inject a dose of reality, this isn’t something completely revolutionary or new that the Campfire team have cooked up here, just a very good implementation of the midrange. It is noticeable mainly when you switch back to other IEMs after a session with the Solaris – the other gear (even things like the Zeus) just feel a little flatter overall. I don’t think this will be the “ultimate” midrange tuning for all genres of music, but for fans of guitar and piano based genres, or western rock and pop music, it should pretty much tick all of the boxes that need ticking.

Treble

The treble on the Solaris is handled by the same twin balanced armature setup used in the higher tier all-BA models in the CA range (the Jupiter and Andromeda) and also in the first hybrid in their range, the Dorado. It uses their proprietary Tuned Acoustic Expansion Chamber (TAEC) technology, using a 3D printed resonating chamber to remove the need for sound tubes and “open up” the sound in the high frequencies to allow better extension and air. As can be testified by their various other models, this works, with the Solaris inheriting a few traits from its greener sibling the Andro in both extension and shimmer. As has already been stated, it isn’t a full-blown Andro clone up top, however, coming across a little darker and more grounded in tone than the lighter and brighter all-BA model. I have not heard the limited edition SS (Stainless Steel) version of the Andromeda, but that is purported to have slightly smoother and less sparkling highs, so I suspect it will have more in common with the Solaris in that respect.

There is a crispness and lightness here that still makes the music sound wide open and airy, but also a solidity and thickness of note that stops it from completely floating off into the upper atmosphere. The effect is more reminiscent of a concert in a wide open field than a large auditorium to my ears – sounds float away and fade out, but lack the defining boundaries of a large space to give them that reflective sense of scale.

Going back to “Starlight” by Slash, the dissonant guitar harmonics in the intro are sharp but still weighty, glistening in the ear with an analogue tone that stops them grating like they can on thinner monitors. “Chi Mai” by the classical fusion violin duo Duel sounds majestic, the mix of fluttering synth notes and sharp and emotive violin building to a sparkling crescendo. Violin sounds rich, the vibrato of finger on violin neck coming through clearly with each note that is bowed or plucked. The electronic accompaniment occupies the space above, lightening the tonality without overpowering, providing just the right level of accent to the sound.

“Go” by The Chemical Brothers follows a similar theme, the swirly keyboards that kick in around the 1:20 mark whipping across the top of the soundscape, opening up the higher octaves without sounding overly bright. It envelops you, bringing the height of the stage into full relief. Moving to something more analogue, “The Golden Age” by Beck plays wonderfully, with its chimes and xylophone style percussion filling the space around your ears with an expanded sphere of high notes, full of detailing and texture, popping in the ear like little bubbles full of sound.

That sounds like an overly flowery piece of hyperbole, but it is the closest my brain can get to a descriptor, unfortunately. Treble is solid but extended, carries sparkle but isn’t overly thin or delicate (unless that’s the way it is recorded in the track) and is absolutely packed with fine detail and texture. Despite saying that the treble has weight, this isn’t a dark monitor by any means, and for fans of an ultra dark or rolled off treble tuning, the Solaris probably shouldn’t be at the top of your wishlists. It extends effortlessly past the upper reaches of my hearing without any apparent strain, but doesn’t lose it’s analogue tone while doing so, staying true to the overall sound of the IEM without resorting to any particularly obvious spikes or hotspots in the upper ranges (that doesn’t mean they aren’t there, they just aren’t obvious TO ME). This is pure treble, with plenty of inner resolution rather than specific frequency sharpening, making it easy to listen to for extended periods without any dose of fatigue.

Overall, if you are looking for a clone of the Andromeda, the Solaris won’t quite get you there, but if you are happy trading just a touch of that wide open treble fizz for a meatier and more analogue tonality, the Solaris is an exceptional IEM in this frequency range, providing some of the most musically enjoyable treble I’ve heard yet.

Soundstage, separation and imaging

The Solaris throws out a fairly wide and deep soundstage, pushing about 30cm outside of the head in all directions, forming a perfect sphere with excellent height and depth. It feels broad, but doesn’t give the feeling of huge vastness in its sonic image, mainly due to the size of the individual notes on the stage.

The Solaris has inherited the “big sound” of its DD predecessor the Atlas here, presenting vocals and guitar in a larger than life sizing, almost as if the music had been blown up with the classic iDevice  “pinch to zoom” gesture in the ear, but while still being able to see the full picture. It’s this sense of scale which leads to an almost speaker-like feel to the Solaris presentation, the music giving the impression of filling the available space around the listener’s ears without seeming crowded or claustrophobic.

In terms of separation, the Solaris won’t blow you away with a sense of distance between far left and far right panned instruments, but rather impress with a scale that can leave other IEMs sound a little small until you readjust. Playing something like “Trouble” or ”Shelter” by Ray Lamontagne, the hard-panned drums and bass parts push outside my head further than a lot of IEMs I own in either direction, but don’t feel as distant from the vocals in the centre image. The Solaris has truly TOTL layering capability, which helps in this regard – no matter how densely packed a section of the audio spectrum is, the Solaris manages to lay each instrument and noise down cleanly in its own little slice of the universe, with no sense of congestion or blurring.

This is put to the test with “Coming Home” by Sons Of Apollo and “Take You With Me”  by Tremonti. The former is a track which is stacked higher than a Black Friday sale shelf, the bass guitar and electric both shadowing the same riff and overlaying the busy kick drum and tom tom phrases underneath. On less capable monitors this song can collapse into a enjoyable but muddled wall of noise in centre stage, but the Solaris remains impeccably composed throughout, carrying the texture of the bass, the bite of the guitar and Mike Portnoy’s roving drum fills with equal ease. This is where the bass tuning really comes to the fore, the extra emphasis on speed and definition over sheer quantity from the ADLC driver really helping the Campfire model retain clarity at all times. The Tremonti track is a blast of high speed guitar and kick drum patterns, and again the Solaris is clean and crunchy throughout, the speed of the drivers matching the music without any blurriness.

This is one of the areas where the Solaris obviously shows its credentials at the top table, presenting a large and impeccably positioned sound, with instruments laid down in solid locations across the stage and everything having enough room to breathe, without dissecting the music into an analytical pile of component parts. Another area where the TOTL card gets played shamelessly is with the imaging capability of the Solaris. The 3D stage and clean layers of sound allow the CA flagship to present music with a very specific sense of location and positioning on the soundstage, giving both width and depth to individual instruments, dropping them carefully into their own clearly defined slots in the ear rather than spreading them between the ubiquitous three left/centre/right musical “blobs” that some lesser monitors will resolve into.

This allows the listener to hear further “in” to some well recorded tracks, with each instrument possessing more of a lifelike feel as it sits in a specific location in the overall sound, mimicking the sort of feel you get from a live acoustic gig, and helping with the effortless sense of immersion that these IEMs can manage with the right track. The fact this can be done without losing the analogue tone and natural feel to the sound is potentially the Solaris’ greatest achievement IMHO – allied to a natural inner resolution that can dig into the sound, this really is something pretty special to experience with the right tracks – if you have any binaural recordings, I strongly recommend tracking down a Solaris to try them out with.

Power requirements and gear synergy

The Solaris is roughly similar to other CA models in terms of sensitivity and overall driving requirements. If you haven’t owned one before, this basically equates to being able to drive the Solaris to acceptable listening volume with two paper cups and a piece of string, and listening to it hiss like a drunken polecat with anything less than a jet black source. Personally, I find the noise level to be pretty low with both my N5IIs and DX200 / Amp 8 setups, but it does give a little more noise with other gear I have tried it with like my Questyle CMA400i desktop rig. While you can get pretty high volume without much effort, the DD driver in the Solaris can soak up a pretty obscene amount of wattage, so I personally find that I get the best results in terms of driver control and texture in the low end with my DX200/8 on high gain, the additional bump in output power giving a little more grip to the DD elements of the sound. The trade off will come with increased hiss on some sources as a result, but as mentioned, I don’t really notice with the Ibasso, so as always, YMMV.

The Solaris also shares another trait of the CA line, with an impedance curve in the BA elements that react differently to sources with different output impedance. Basically, the higher the OI, the more emphasised / sharp the treble in my experience, so if you prefer a more crystalline and etched feel to the sound, using a higher-OI output device will allow you to tinker with some elements of the sound there. There is plenty of info on this in the various Head-Fi threads for Campfire IEMs, and there are some notable outliers (like the Questyle devices with their unusual amp designs), but as a rule of thumb, anything hovering around the 1 Ohm mark should be fine for an “optimal” listening experience.

As mentioned above, my “go to” sources for the Solaris are the N5IIs and the DX200 – the Solaris is relatively transparent, so will benefit from the highest quality source components you can provide in the chain to really get the most out of the available sound. Both DAPs mentioned provide a nicely weighty feel to the low end, with the Cayin feeling a little more dense at the bottom of the frequency, with a wonderfully black background. It loses out a little in overall presentation to the higher-performing DX200, which scales a little better with the Solaris to present a more fully 3D picture in the ear, with more definite placement across both the X and Z axis.

Another surprisingly good pair up is the LG V30, with the mobile phone “audio flagship” sounding excellent in terms of noise and overall detail retrieval, just lagging behind the Cayin and Ibasso DAPs in a little micro-resolution and imaging prowess. Unless you have a particularly noisy source I would imagine most things will play nicely with the Solaris, but it does have a tendency to expose any gaping flaws in the chain, so sources with particularly high OI or any areas of rawness in the response probably won’t provide the best matches.

One frustrating pair up is the ALO Continental V5 amp; while the Solaris don’t need additional power, the tubey goodness of the CV5 was too good an opportunity to pass up to see how it would match up. On a musical level, it pairs wonderfully well, accenting the organic tone and throwing a fully rendered 3D image into the ears from the off, accentuating the strengths of the Solaris without making it sound too warm or smooth. Unfortunately, this comes with a level of hiss that is higher than I am comfortable with, making the pairing one that is ultimately a little frustrating for me. Admittedly, you can use something like an IEMatch from iFi to alleviate that, but this has a slight effect on the overall tonality to my ears, negating some of the wonderful richness the CV5 throws out with this pairing. If you aren’t sensitive to hiss, then by all means go for this pair-up, but if you can’t stand a hissy source, this probably won’t be the best combination you can find for the Solaris.

Tip choice

The Solaris is quite divisive when it comes to best tip choices, with the bigger shells of the IEM giving various opinions on what sort of tip is best for each individual ear shape. From the included tip range, I prefer the CA Marshmallow foams over the ordinary silicon tips or the Final E-series tips, as they provide the most stable seal and fit for regular wear. In terms of sound, the Final tips probably edge it for me in terms of sonics, giving a little bump in the bass and additional crispness in the higher ranges, but the fit it a little problematic for me so I keep losing seal in longer listening sessions.

As far as after-market tips are concerned, I have had the most success from a “regular” tip with Spiral Dots tips from JVC, the wide-bore and relatively shallow fit allowing a more stable seal in the outer ear and a nicely neutral effect on the overall tuning. I personally find the best synergy with a set of custom-moulded silicone ear tips from Polish manufacturer Custom Art, as they combine the cleanliness of the Spiral Dots with the same sort of isolation provided by foam (which aids mainly with bass slam), plus a rock solid fit which locks the Solaris shells firmly in place while I’m up and about (yes, I wear these on my commute sometimes!). Obviously, custom tips aren’t an option for everyone, but given the relative cost of the Custom Art solution, I wouldn’t class it as prohibitive in comparison to the cost of the IEMs and the source you will be using to run them with, so well worth looking into if you want to get the best combination of seal and fit.

Comparisons

Stealthsonics U9 – (1x DD / 8 x BA hybrid, $1099)

The U9 is the current flagship from Singapore-based IEM firm Stealthsonics, packing one 10mm dynamic driver and 8 balanced armatures in a 4-crossover design. Much like Campfire Audio, the team at Stealthsonics are quite comfortable to trumpet various unique technology they use to achieve their house sound, with the team at Stealthsonics concentrating on material composition on the shells themselves along with some advanced airflow modelling in the nozzle to deliver the best sound they can.

The U9 packs slightly more drivers into the shell, using 2 armatures for the midrange, two for highs and a quad-driver array for “super highs”. The DD is the same size, but utilises a more standard design than the ADLC diaphragm used in the Campfire model. In terms of overall sound, the U9 is an impressive performer in its price bracket, with a crisply detailed sound and razor-sharp instrument placement. Despite its hybrid design, the U9 isn’t particularly bass-heavy, with the DD being tuned in a very similar manner to the Solaris, pumping out decent impact in the sub-bass regions with an emphasis on speed and impact over sheer volume. It feels a little less full and rounded than the Solaris, following an almost flat or neutral response – extension is similar on both models, digging deep into the recesses of sub-bass without any noticeable roll-off. In terms of layering and detail retrieval, the U9 driver is no slouch, but it doesn’t quite have the stellar response of the Solaris, lagging a little behind the Campfire model in overall texture and fine detail. Neither model will be suited for extreme bass heads, but the Solaris is definitely the juicier of the two in universal configuration (the U9 is also available as a custom IEM for an additional $400, bringing it into line with the price of the Solaris and potentially improving bass response slightly due to the additional seal).

Mids are a little thinner and more distant on the U9, with it painting a slightly less intimate picture in terms of both stage position for the vocals and overall note size. The U9 feels a little cooler and leaner in tone, with more emphasis on the edge of notes and a sharper and more overtly detailed response. Resolution is one area where the U9 is noticeably more emphasised, the more neutral tuning allowing the thinner notes to eke out high levels of micro-detail with well recorded music, in comparison to the more laid-back and natural sound of the Solaris. This does come at the cost of a little of the Solaris’ organic timbre and tone, with the U9 sounding more “processed” in direct comparison. The colder tone also provides a more analytical feel to the presentation.

Treble is sharper and more emphasised on the U9, again feeling a little thinner than the Solaris in both both tone and overall weight. The 6 drivers responsible for the higher frequencies provide a superbly linear extension up past the limits of usual human hearing, allowing the U9 to paint an extremely detailed picture in the high ranges without any issues. Despite the extension, the tuning is devoid of any peaks or hotspots, so the U9 is always smooth, being slightly more forgiving on hotter or more poorly mastered tracks in this respect. The super-tweeters also allow the U9 to paint a lot of supersonic “room noise” and other sonic cues into the sound if it is there in the underlying audio, competing well with the Solaris in terms of providing a solid and holographic image, with neither IEM pulling ahead significantly here. Stage size feels similar on both, with the Solaris providing the bigger picture and the U9 taking a more widescreen approach.

In terms of driving ability, the Solaris is the easier IEM to drive, with the U9 requiring a little more power to get to the same listening volume on my usual gear. U9 is less picky with source OI, staying pretty stable with differing output impedance and offering not much in the way of hiss with any of my current sources.

Build is very different on both, with the U9 being made of a super-light rubberised polycarbonate type material in comparison to the all-metal design of the Campfire model. The Campfire model feels a notch up in both durability and overall aesthetics here, providing a much sturdier feel. The U9 counters by weighing almost nothing, so if long term listening comfort is a concern, the Stealthsonics IEM will probably be a better bet as it will disappear into your ears with no obvious strain due to the lack of weight. That being said, fit and ergonomics definitely go to the Solaris for my particular (large) ear shape; the U9 use a rounded shell design reminiscent of the Noble Audio universal shell designs, but for me this translates to a very shallow fit and some difficulty getting a solid seal in the ear with most tips. Once sealed, they are Uber-comfortable, but there is definitely more fiddling required to get (and maintain) a seal with the U9 in comparison to the more ergonomic Solaris.

In terms of the overall package, Stealthsonics provide a decent if not mind blowing loadout compared to CA, with a similarly sized (but lower quality) carry case, a variety of tips and two IEM cables from Singaporean manufacturer Null Audio as standard, one with mic and one without. Both cables are terminated in standard 3.5mm single-ended format, so the mic is the main distinguishing feature, which is slightly unusual given the “audiophile” market they are obviously shooting for with this model. Cables are a good standard and ergonomically excellent, but not quite up to the full after-market experience of the ALO SuperLitz in terms of looks.

Overall, the U9 is a well performing hybrid in the $1000+ market, with a strong analytical sound and excellent technicalities. It offers similar imaging prowess to the Solaris, but diverges quite significantly in terms of tuning, erring more towards a cooler and thinner tonality, with less physical dimension to the individual notes (both in terms of weight and overall “roundness”). As a result, while I am impressed with the technical prowess of the Stealthsonics model, the Solaris is the more engaging musically, giving a more immersive and enjoyable musical ride when you just want to lose yourself in a track. Add that to the more premium feel to the build and packaging, and I would find myself siding with the Campfire model if I had to choose between them – fortunately for me, I don’t.

Empire Ears Zeus-XR – (c. $2300, 14 x BA custom IEM with 8 crossovers and tuning switch)

The Zeus-XR is the legendary former flagship of the Empire Ears “Olympus” line, sporting 14 balanced armatures and a 7 or 8 crossover design, depending on which tuning you select on the inbuilt switch. This is a combination of the previous Zeus-XIV and Zeus-R models, offering both tunings in the same shell. At time of launch, it was the IEM with the highest balanced armature and crossover count in production, and while it has since been surpassed by models from Rhapsodio and 64 Audio in that particular race, it maintains its position as a summit-fi in ear in terms of sheer technical prowess to this day.

Prior to the launch of their hybrid series, the Empire Ears lineup were well known for their midrange, and the Zeus is based firmly around that mid-centric house sound. Starting with the bass, the Zeus (in both configurations) has less substance than the Solaris, with a snappy but flattish sounding bass tuning that is more tilted towards mid-bass than sub-bass. The dual-BA woofer setup is surprisingly impactful for an all-armature driver, but it definitely lags behind even the restrained bass of the Solaris in terms of overall presence. Detail levels and texture are high with the Zeus in both configurations, but again it lags a little in terms of layering compared to the Solaris, and doesn’t have quite the same level of richness in bass-heavy tracks. The Zeus often gets unfairly labelled as a “bass-light” monitor, but I think it is capable of digging out bass if it mastered into a track, but here it shows its BA roots compared tot he thoroughbred DD packed inside the Campfire model. Sub bass is won easily by the Solaris, with the Zeus mustering a little tickle on serious basshead tracks, but not providing the same sense of physical impact the Solaris can muster with the same tunes.

Moving up to the midrange, the Zeus offers a forward and thick mid presentation, giving a slightly denser feel and more forward tuning in the “XIV’ configuration and a more neutral tonality with the ‘R” switch engaged. In either mode, the Zeus sound marginally more forward with vocals than the Solaris, sitting in the forefront of the sound. Where the Solaris excels in the bass, the Zeus pulls slightly ahead here, presenting a dense but ultra-detailed midrange with more layers than a prizewinning Gallic onion. The Solaris sounds a touch more organic, and has a more diffuse quality in comparison to the solidity displayed by the Empire Ears IEM. The Solaris also stacks up surprisingly well in terms of resolution, but can’t quite match the sackful of balanced armatures providing the grunt in the Zeus engine room, with the Zeus finding the smallest nuance and inflection and painting it effortlessly into the ear. To be fair, not many IEMs can best the Zeus in terms of sheer clarity, so it’s a surprisingly good effort from the single BA and DD powering the Solaris here.

Treble is similar on both, with the Zeus feeling a little zestier and more sharp than the crystal clear but smoother Solaris. Neither IEM is prone to sibilants or harshness, so there are more similarities than differences here, with both designs relying more heavily on natural resolution over strategic peaks in the upper end to pull out details.

Stage size isn’t too different, with the Zeus feeling similarly wide but not quite as deep as the Solaris, throwing more of an oval stage in my mind compared to the sphere of the CA model. The Solaris again feels “bigger” in terms of note size, but this is countered slightly by the more prominent vocal staging. One area where there is a notable difference ins the depth, with the Solaris definitely feeling more three dimensional compared to the flatter presentation of the Zeus. This is purely a comparative observation, as the Zeus is far from a flat sounding IEM, but it helps to highlight again the prowess of the Solaris in this respect.

With regards to power, the Zeus and Solaris are actually very similar, with the Zeus actually being marginally more difficult to drive on my DX200, which is a little surprising. One thing to note is that the Zeus hisses a LOT more than the Solaris with this pairing, making it sound almost jet black in direct comparison.

In terms of packaging and build, this is a draw. The EE model comes with a superb (and superbly huge) hard carry case, and a premium aftermarket cable as standard (currently the Effect Audio Ares II, although mine shipped with a BTG Starlight cable),. Build quality of the CIEM is first rate, matching the Solaris for aesthetics and obviously moving ahead in fit (although the custom eartips I use are made from the same mould as the Zeus impressions, so the fit is actually remarkably similar for my particular circumstances).

Overall, this is a closer race than the U9, with the Zeus providing an addictive Ley rich and detailed midrange presentation that is pretty unique in the current IEM landscape, throwing out gobs of detail in a rich and smooth feeling package that excels with vocal heavy or acoustic music. The Solaris again sounds like the more organic and natural of the two, with a more impactful bass and a deeper and large sonic image. They are different enough that they will appeal to differing audiences, and are both comfortably top-tier in raw performance, so I’m not able to pick a favourite here. The Zeus would probably get more ear time for acoustic of more complex music, with the Solaris being my go-to for rockier music or more chilled vibes where I just want to drift into the soundscape.

Campfire Audio Atlas – (c. $1299, single 10mm ADLC dynamic driver)

The Atlas is the dynamic driver flagship of the current CA range, sporting the same single 10mm ADLC driver as the Solaris and a much bassier flavour. It shares a little of the shell design with its hybrid older brother, with the same stainless steel front assembly and grille. In terms of size, the Atlas is a lot smaller than the Solaris, but feels similarly heavy in the hand due to the solid steel body and small size, being designed for wearing downward in a more traditional “earbud” style (although it can be worn over-ear / IEM style with a bit of effort).

In terms of packaging and build, it will be a draw, with the Atlas sharing an almost identical package and loadout (albeit in slightly smaller dimensions), right shown to the tip choice and CA pin. The two areas of difference are with the case and the cable. The case is the same classic Campfire Audio design, but approximately half the size of the Solaris case, so a lot more pocketable. The cable difference is also one of size, with the Solaris being sold with the thicker ALO SuperLitz cable, whereas the Atlas is paired with a thinner ALO Silver Litz cable. Both are twisted rather than braided, but the Atlas is paired with a pure silver cable design as this was felt to better complement the sound than a more standard SPC. Both are high end after-market cable quality, but the SuperLitz is a thicker and more physically (and visually) impressive cable, with similarly good ergonomics and low cable noise. One plus point for the Atlas Litz is the lack of memory wire (due to the fact it is intended to be worn down), which makes it easier to wear with other MMCX in-ears in my collection.

Sound wise, these are two VERY different takes on the evolving Campfire Audio “house sound”. The Atlas is a brassy, impactful sonic punch to the eardrum compared to the more restrained and airy Solaris. It is still balanced in its own way but it is more a balance of dialling everything up to 10 and still keeping it coherent and separate rather than the more delicate naturalness of the hybrid model.

Both sub and midbass are present in more quantity on the Atlas, reaching just as low as the Solaris but with a fair few dB more oomph across the board. Whereas the Solaris has a solid sub-bass slant that tails off into the mid-bass, the Atlas stays almost flat throughout the range in direct comparison, providing a fair bit more punch on things like bass guitar and kick drum beats. The Atlas is the more visceral and animated IEM, building on the foundations of its predecessor the Vega. Texture and layering is a draw, as you would expect from the same exact driver design. Detail is possibly slightly more noticeable on the Solaris due to the decreased sound pressure, but it is a very close call. The Atlas has speed for a single DD, but seems a little less crisp than the Solaris in direct comparison, again probably due to the lowered emphasis. The Atlas is a true basshead capable IEM, so if you are looking for real lower register slam, the Atlas definitely pulls ahead here.

Mids are differently presented, with both having a similar position on stage, but the Atlas presenting in a thicker and less overtly detailed way. The mids are still free of mid-bass bloom so don’t feel veiled or blunted, but the additional warmth imparted from the bass below gives them a chunkier and less open feel to the more organic tone and clearer separation evidenced by the Solaris. Atlas excels with guitar music, giving an edge and crunch to guitar transients and chugging rock riffs that is more in your face and involving than the more laid back Solaris. This energy is addictive, but is has an “always on” quality that makes it difficult to drift into the music as the same way as the Solaris – both have excellent detail and clarity, but the Atlas is definitely the more energetic presentation, making it more of a specialist than the Solaris’ natural jack-of-all-genres tuning. The Solaris feels more spacious to my ears, giving a slightly better sense of resolution due to the clearer air around each note.

Treble is a battle of BA vs DD, with the Atlas tuning showing decent crispness and extension, with a nice sharp edge around notes that helps cut though the thickness below. The Solaris have a more organic and airier tonality, with a more expansive presentation and a dash of sparkle that makes them pop a little more than the more earthy sounding Atlas. Clarity seems to be a little higher on the Solaris, the dual-BA and TAEC chamber technology providing a more crisply resolving sound in the ear. The additional space and headroom around the treble notes again allows for a little more of the subtle micro-detailing to come through in well recorded tracks, things like scuffs on guitar frets and more distant room noises throwing themselves into sharper relief in the ear.

In terms of separation and layering, the Solaris has a clear edge here. The Atlas has TOTL DD credentials, and backs this up with some excellent technicalities, but the Solaris just has slightly more space around each note and a dash more crispness in the presentation that marks it out as a slight notch up in this regard. As far as power requirements go, the Solaris is the more sensitive of these two IEMs, requiring less juice to drive to a similar sort of volume.

These aren’t two completely different monitors in terms of overall tuning, rather they are two ends of the same spectrum. Both have a great musical / natural tonality, with decent to excellent technical prowess and a killer sub bass. The Atlas takes the warmer, bassier road, excelling with tracks requiring lots of low end or punchier rock tracks. The Solaris puts its efforts into turning your head into a well damped speaker listening room, playing with clarity and emotion across all genres and drawing you into its own little “cone of music”. The Atlas has been my daily driver since I got it, and for day to day use on public transport etc or when I just want to rock out with some high tempo beats, the additional bass and thickness is preferable. When I am at home or at my desk, the Solaris has now supplanted it in my personal music listening, which is no mean feat. Both are excellent, and both have an equal place in my collection – if you are after the absolute best in terms of imaging and resolution, the Solaris would be my suggestion out of the two, but if you need something almost on the same level but with a healthy dollop more bass, the Atlas won’t steer you far wrong either.

Overall thoughts

The Solaris is an impressive culmination of the last few years for Campfire Audio, taking the building blocks of the earlier models in their dynamic driver and balanced armature designs and slotting it all together into a remarkably coherent and compelling sound. There is a balance that provides musicality without more than a hint of colouration, giving a transparent window into the sound that feels more like a live gig or a good speaker setup at times with the right track. It’s no exaggeration to say I’m a huge fan of Campfire Audio gear, so please bear that in mid when reading these comments, but it’s also no exaggeration to say that for me this is the best IEM that Ken has made to date. It lacks the raw visceral impact and rampaging sense of fun that characterises the Atlas, but it replaces it with a lifelike and beautifully rendered sonic landscape, placing instruments and voices around with such realism that you forget you are listening to an IEM and just think about listening to the music instead.

The Solaris have only just missed out on a 5-star rating across the board due to the slightly fiddly fit with certain tips, but as always, a quick reality check: these IEMs are not the second coming of whichever deity you worship, they are not the best thing that will ever be heard by everyone ever (and in some cases probably won’t even be in some people’s top five, depending on preference). They should appeal to a pretty broad slice of the audiophile market with a tuning that is suitably all-round, but could be described as bass-light by Atlas fans and not trebly enough by people expecting a carbon copy of the Andromeda. They might not play well with some pop music, and certainly aren’t forgiving of badly mastered recordings. All of these things are true, but what is also true is that these are a rare blend of technical capability and a natural musicality that the entire team at Campfire Audio can (and should) be proud of. If you get the chance to hear these IEMs at a Canjam or local audio retailer, please do your ears a favour and do so – they might just be the answer to the questions you never know you had about how good audio can be with the right gear. As always from the Portland manufacturer, nicely done.