Astrotec Phoenix: Sub-Bass Royalty


Today we’re checking out Astrotec’s newest flagship, the Phoenix.

Their previous flagship, the Delphinus5 equipped with five Knowles armatures per side, was and still is one of my favourite earphones. It is one of the most neutral and flat sounding reference products I’ve heard, all the while looking fantastic in the process and being comfortable to boot. Still, the way it was tuned was certainly not for everyone. The Phoenix, with it’s hybrid dynamic/electrostatic setup, has a sound that is much more exciting and widely appealing. Add to that the use of high end materials in a timeless design and the Phoenix is perfectly capable of carrying the flagship mantle.

Let’s take a closer look, shall we?

P1070079 (2)

What I Hear The Phoenix doesn’t go for a neutral, balanced signature, instead opting for something that highlights it’s two greatest features/assets; the custom dynamic and twin electrostatic super-tweeters.

The treble out of the Phoenix is on the lean side and sees emphasized peaks in both lower and upper regions giving the Phoenix a bright, sparkly, airy presentation that is absolutely packed with detail and full of energy. There is nothing laid back about this upper range, so you treble sensitive folks beware. Everyone else will be treated to an impressively snappy attack and rapid decay rivaling most armatures. Control is generally quite good, though there is a hint of looseness in the brilliance region that crops up on occasion. Some instruments, cymbals in particular, will have a slightly metallic edge to them so the presentation isn’t going to be quite as natural as some will be looking for. A slightly less emphasized treble presentation would have suited the Phoenix, especially since I think the low end is the Phoenix’s ace in the hole, its raison d’être so to speak, but boosting the treble to show off the generally impressive performance of the twin electrostatic drivers makes sense given the effort necessary to make them work, and the cost involved in using them in the first place.

Most of the midrange is recessed save for an upper peak (not 3K for those that hate it, instead you get a 2K peak. Oooooo!) that brings presence back and keeps vocals prominent, even amidst the mighty low end and enhanced treble emphasis. The presence region bump that gives the Phoenix’s treble so much detail carries down into the midrange giving vocals and instruments outstanding clarity and coherence. Deeper male vocals will sometimes come across a bit under-emphasized, but they still remain clear and easy to understand. Detail and clarity are definitely in the Phoenix’s wheelhouse. Timbre is a bit less consistent. While the mids and bass are handled well by the dynamic, as you encroach on the twin super-tweeter’s territory some of the realism is lost; see the previously mentioned metallic edge. So while the tonality of the dynamic and electrostats are slightly misaligned when taken as individuals, the resulting sound when combined is still very satisfying.

A big part of that is because of the bass. After using the Phoenix on the regular for nearly a month and comparing with a wide variety of gear from budget earphones to more comparably priced and top of the line models, I can confidently say this is the most entertaining and speaker-like bass I’ve heard to date. Astrotec’s custom dynamic has what feels like near unlimited extension with emphasis to match, and as a result gives off a level of visceral feedback I’ve never felt from an earphone before. It’s a wholly unique presentation, and I can’t think of a single product I’ve heard that can match the intensity of what the Phoenix’s sub-bass presentation is bringing to the table. It’s not sloppy one-note bass either, presenting itself with plenty of texture and nuance when needed. The feeling is one of dynamism and control, regardless of what is being reproduced. And that applies on extremely quick bass notes too. I was expecting, given the tremendous depth and lower end emphasis, that the driver would on the sluggish side and trip up when things got busy, but nope, not the case. I would love to see Astrotec re-use this driver in a future single dynamic earphone, simply to allow that bass the full spotlight.

When it comes to staging the Phoenix is mighty impressive. The slightly lean presentation and upper range emphasis combined with that intense, expansive low end sets the expectation for a capacious feel. The default vocal positioning is just in the outer ear which helps pull the stage back. Width is excellent with notes and effects easily able to trail off well into the distance. Depth is stellar too, allowing for heavily layered tracks to pull apart and instruments to spread out and remain clear and separate. Channel-to-channel movement is clean and precise with drums being a standout when they’re mixed to rapidly dart from side to side. Acid jazz and a couple of my favourite EDM genres, liquid drum and bass and psy-trance (Infected Mushroom in particular), do a killer job of showing off the Phoenix’s impressive staging qualities.

Overall I find the Phoenix to be a unique and intriguing listen. If looking at it purely from an objective standpoint, subbass emphasis is much too excessive and the treble could be smoothed out a bit. Subjectively, it’s a whirlwind of an earphone and I’d be terribly disappointed if that subbass wasn’t there. That for me is what makes the Phoenix so special, and is the reason why it ends up being so addictive and hard to put down. That low end combined with a strong technical side and a cavernous sound stage pools together to make the Phoenix quite unlike any other earphone I’ve come across, but in a good way.

Compared to A Peer (volumes matched with Dayton iMM-6)

HiFiMan RE800 Gold (699.00 USD): The RE800 and Phoenix take very different approaches to sound reproduction. Where the Phoenix is unabashedly bold and bassy, the RE800 take on a more reference approaching with a splash of boosted treble to spruce things up.

Starting with the bass, like the Phoenix the RE800 offers up excellent extension with great speed, control, and a hint more texture, but emphasis is greatly downplayed in favour of a more neutral presence. The Phoenix really pushes the subbass focus while downplaying the midbass presence the RE800 needs to ensure it’s low end is not overshadowed by the mids and treble.

Both earphones have a clean, crisp midrange with excellent clarity and coherence. The RE800 is more prone to pulling sibilance and presents with a drier, more snappy timbre despite the extra midbass warmth over the Phoenix. I also find it presents with more rapid kick on percussive notes, and has vocals that better cut through the mix, though not everyone will enjoy how forward they are. Personally, I prefer the less clinical, slightly more laid back and natural-ish mids of the Phoenix.

Treble is where the two once again differ greatly, thanks to the RE800’s stronger emphasis through both presence and brilliance regions. I find this results in more shimmer and sparkle than what the Phoenix can output, while also adding a bit more space and air between notes thanks to a less dense presentation. If increasing the volume to bring up the midrange, it can result in fatigue. You don’t really need to do this with the Phoenix whose subbass focused sound and more even transition from mids through to the upper treble means you can tailor volume to best emphasize those regions without worrying too much about the low end taking over, unless of course you are fatigued by high subbass quantities.

Both do sound stage very well though I’d say the Phoenix has a clear advantage. First, vocals are immediately less intimate with a default position set just in the outer ear. The subbass presentation also gives off the impression of additional space thanks to its visceral feedback and the way it can trail off into the distance. The Phoenix’s superior imaging, layering, and separation also make the overall presentation more rich and dynamic.

Going back and forth between these two showed they were less competition and more complimentary offerings. The Phoenix is much less analytic (though it gives up little in terms of raw detail) and to my ears more entertaining thanks to that mad subbass and impressive sound stage, whereas the RE800 feels more buttoned up and precise. One is for when you want to listen casually/for fun, the other for when you’re ready to get down to business and listen seriously.

Campfire Audio Solaris (1,499 USD): (This was a comparo written for one of my Insta followers. Figured I’d bring it into the review with some minor edits) Bass is in my opinion the Phoenix’s best quality, and damn does it ever do it well. Compared to the Solaris, the Phoenix’s low end is notably less linear and more emphasized, particularly in the subbass region. The Phoenix can move air like no other earphone in my collection. It’s definitely going to be too much for some, but I personally find it pretty awesome. Especially since it has the control and texture to back it up. The Solaris sounds a lot more polite and restrained.

Solaris has a more linear midrange structure with a dip in the upper mids compared to the Phoenix which spikes in the same spot. As a result, I find the Solaris to sound more timbre accurate but with vocals that lack the same body and ‘pop’ of the Phoenix. Coming along with that is a bit more sizzle in sibilant areas making the Phoenix a bit less forgiving of track flaws. Given the few measurements I’ve seen of the Phoenix, I was expecting it’s timbre to be pretty out of wack, but it’s closer than I was expecting. I definitely has a unique sound to it though, for better or worse.

That upper mid spike slightly carries over into the lower treble giving the Phoenix an edge, imo, in overall clarity and microdetail. It stops just of short of crossing over into being harsh and overblown, though it’s definitely not suitable for treble sensitive listeners. Upper treble is similarly emphasized with the Solaris having a very slightly more broad, less focused peak, that tops out a little higher in the range. As a result I find it to display a bit more sparkle, along with better control, while the Phoenix displays more sizzle.

The Phoenix’s somewhat wavy, imbalanced tune results in a fantastic stage that is broad and open. Vocals default just outside the ear with the reserved midbass and treble presentation adding a ton of space. While I wouldn’t say the stage itself is larger than what the Solaris outputs given how effects travel into the distance, it sure feels like there is more space and air between notes. I’d give the Poalris the edge in terms of instrument separation and layering, while the Phoenix keeps up with the impressive imaging of Campfire’s offering.

As much as I love the Polaris, the Phoenix’s tune speaks to me more. I think the Polaris is clearly the superior product from the perspectives of build refinement and technical competency with a more balanced tune and realistic presentation, but if you’ve been following my content for any length of time you’ll know my preferences lean far more towards entertainment factor than accuracy. I’d rather listen to the Phoenix due to that wicked bass set within a pretty stonkin’ large sound stage.

Important Notes The Phoenix is laughably tough to drive. You need a good amp and preferably a balanced out option. The above impressions vs. the Solaris were taken with both running through a standard single ended 3.5mm output via the EarMen TR-Amp. Bring balanced into the mix and those comments regarding the layering and separation gap pretty much disappear. The Phoenix sounds notably more impressive balanced. Keep in mind that I generally care not an iota about going balanced because most of my experiences have been that it does nothing but improve loudness. Not the case here, even if measurements result in virtually identical curves.

In The Ear **Keep in mind that this is a prototype and not a release version. I was told the sound is final, but the build is not.** Astrotec went all out with the Phoenix in their goal of crafting a true flagship. This is heard in the custom dynamic and twin Sonion electrostatic super tweeters, but also seen in the overall physical design. First are the titanium and aluminum alloy face plates which dominate the exterior of the earphones. It reminds me of a sun or the aperture blades of a wide open lens. It is fairly subtle, but upon closer inspection looks fantastic. The housings themselves have been handcrafted from rosewood into a familiar half-moon shape with inner protrusions that effectively follow the contours of the outer ear. For the nozzles Astrotec went with brass which fits the Phoenix both aesthetically and acoustically. Lastly, the MMCX ports that stick out very slightly from the top of each earpiece are surrounded in plastic mounts which should offer some additional protection from sudden shock, such as when the earphones are dropped.

The Phoenix’s included cable is a bit of a mixed bag for me, though predominantly positive. You can’t argue against it being a quality item thanks to the use of 6N OCC wiring, reinforced with Kevlar for additional durability. The thick fabric sheath fits well within the natural aesthetics of the Phoenix’s design philosophy. The preformed ear guides are soft and flexible, feeling comfortable around the ear. The y-split is about as basic as it gets, with the inclusion of the chin cinch being a welcome touch. The metal straight jack has a neat ring of knurling for grip, and a stubby but flexible strain relief that will help protect the cable from regular wear and tear. Negatives go back to that cloth sheath which transmits more noise than I’d like from basic movement. It also doesn’t like to wrap up neatly, resulting in mild tangles if you aren’t careful. Lastly, the super comfortable ear guides are a bit too flexible and as a result allow the cable to bounce up and over the ear while walking. As much as I like aspects of this cable, it was one I swapped out the first few listening sessions.

Thanks to the Phoenix’s shapely, low profile design, it is quite comfortable even though it is also quite large and somewhat hefty. Weight is well distributed around the base of the outer ear with the ear guides helping relieve some of the weight. The nozzle is also relatively long and protrudes at a natural angle, again helping to manage the Phoenix’s mild heft. The outer ear filling size, deeper than average insertion, and general design leads to pretty good isolation, even with basic silicone tips. Going on walks at night by a busy main road with the earphones in but no music playing, the sound of vehicles passing by was still audible but considerably dulled. Same could be said for the clacking of a keyboard and nearby voices. With music playing, I rarely found myself having to compensate for outside noise with additional volume.

Overall I find the Phoenix to be a well designed product. The high end materials are befitting of its flagship status, the design is comfortable, and isolation is excellent. I really wish this was a full release model and not a prototype because this particular example doesn’t do the retail model’s fit and finish justice at all. Be sure to head over to Ryan Soo’s coverage on Everyday Listening if you want a second opinion, and to check out the amazing finish of a finalized unit.

In The Box Since this is just a prototype, it did not come with the retail packaging or accessories.

Final Thoughts If you enjoy a spacious sounding earphone with massive, high quality bass and crisp, detailed treble, the Phoenix is likely to be your jam. It’s not neutral, it’s not overly natural, but it is one heck of an entertaining listen that emphasizes the excellent drivers and unique tech within. It’s a nice bonus that the design is as attractive as it is, and that the quality materials like rosewood, brass, and titanium further add to the flagship status this earphone holds within Astrotec’s lineup. Since this is not a release unit I cannot speak to overall fit and finish, but from the images I’ve seen of retail units and comments from others, it looks to be quite good.

As nice as it is, the cable isn’t one I enjoyed using and as a result felt the need to replace it during most of my listening sessions. The somewhat unnatural timbre of the supertweeters can also be distracting at times, mostly with live music, but the more I use the Phoenix the less I care because the bass is just so darn good. This is also a very difficult earphone to get up to volume thanks to some demanding specs. If you lack a quality source or at the very least an amplifier, you’re going to struggle to get it up to volume. And that’s coming from a typically low volume listener.

Overall I find the Phoenix quite satisfying as it offers up a very unique experience at a price range where most aim to be neutral, and that can get boring after a while. The Phoenix is anything but.

Thanks for reading!



Disclaimer Thanks to Astrotec for loaning me the Phoenix for the purposes of review. The sample provided is a prototype unit. The sound tuning is finalized but the build quality does not fully represent a retail ready unit. The thoughts within this review are my own subjective opinions based on nearly a month of use. They do not represent Astrotec or any other entity. At the time of writing the Phoenix retailed for 799.00 USD:


  • Impedance: 32ohms
  • Sensitivity: 85dB/1mW
  • Frequency Response: 5Hz – 40,000Hz
  • Drivers: Dual Electrostatic super tweeters + custom dynamic driver

Gear Used For Testing LG Q70, FiiO BTR3K, Earstudio HUD100, Earmen TR-Amp, Asus FX53V, TEAC HA-501

Some Test Tunes

Supertramp – Crime of the Century

Slipknot – Vol 3 (The Subliminal Verses)

Daft Punk – Random Access Memories

Aesop Rock – The Impossible Kid

King Crimson – Lark’s Tongues in Aspic

King Crimson – Starless and Bible Black

Infected Mushroom – Legend of the Black Shawarma

The Prodigy – The Day is My Enemy

Steely Dan – The Royal Scam

Porcupine Tree – Stupid Dreams

Fleetwood Mac – Rumors

Tobacco – F****d Up Friends

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s