Astrotec Delphinus 5: Defender of the Future


Today we’re checking out Astrotec’s newest flagship earphone, the Delphinus 5.

Astrotec isn’t new to the industry and have been around since 2004 in one form or another making headphones and headsets for a variety of industries. When I first started in the hobby five or so years ago, they were one of the few manufacturers making truly afforable hybrids. If you follow the industry at all, you’ll know that budget hyb rids are a dime a dozen nowadays. Over the last year, Astrotec has made a strong return with premium earbuds via the Lyra Collection series, as well as once again dropping some excellent options in the sub-100 USD realm, such as the AM850 which sheds a hybrid configuration for single, well-tuned, 10mm dynamic drivers per side.

The Delphinus 5, which I’ll call the D5 from here on out, sees Astrotec moving their in ear monitor lineup into a more upscale segment. Priced at around 500 USD, it puts itself in the fray with some heady company. With five Knowles balanced armatures (BAs) per side, “Hi-Res Audio” accreditation from the Japan Audio Society, MMCX standard connectors and gorgeous, gem-inspired aluminum shells, it certainly makes a good first impression.

After spending over a month and countless hours with the Delphinus 5, it’s hard to say that they are anything but stellar (pun intended).



Thank you to Astrotec for arranging a complimentary review sample of the Delphinus 5 for the purposes of this review. All thoughts within this review are my own and are not representative of , or influenced by, Astrotec or any other entity. No financial compensation was provided.





While the D5’s impedance and sensitivity specs are pretty standard for an iem, in practice they are extremely source sensitive. Through the F.Audio S1 the D5 had a smooth, warm tone but was met with a consistent hiss during playback that was very disruptive. Via the Shanling M1 the hiss was reduced, sounding cleanest and more organic on low gain. High gain introduced a cold hardness to the presentation. The HiFiMan Megamini was virtually unusable with the D5. As soon as the device was on, the amount of noise was overpowering and even on the lowest volume, the D5 was uncomfortably loud. It also sounded very harsh and digital. Out of my mobile sources the HiFi E.T. MA8 sounded and paired the best with the D5, by far, though it too suffered from noticeable background noise during playback. Overall sound was neutral and silky smooth with zero harshness or introduced peaks. I also paired it with a number of portable amps, those being the first gen Topping NX1, the Walnut F1, and Auglamour GR-1. Don’t bother… The D5 was also run through my TEAC HA-501 desktop amp briefly. Only on low damping was the hiss virtually eliminated. While the D5 sounded fine through the TEAC, there was a slightly digital edge introduced to the presentation that took away from the more lush, organic sound heard through other sources. Directly out of my Asus FX53V gaming laptop the D5 sounded outstanding. No hiss, warm and smooth with lots of detail. Lastly, I tried running it with the Radsone ES100, a Bluetooth DAC/amp paired up to my LG G5. This pairing sounded awesome too and was completely free of static.

Of all my sources, the only ones that really worked with the D5 were the HiFi E.T MA8, the ES100/G5 wireless combo, and my Asus FX53V. Trying these out with a variety of sources, keeping in mind impedance matching, is a necessity with this earphone since it can sound quite different from one device to the next and it is very subject to background hiss.

Alternatively, you can just pair the D5 with an iFi iEMatch. That little device has made all of the above source matching issues a moot concern since it removes all the hiss regardless of source and keeps the D5 consistent.

Personal Preferences:

I listen primarily to various EDM sub-genres (liquid drum and bass, breakbeat, drumstep, etc.), hip hop, and classic rock. While I enjoy a variety of signatures in my headphones I generally lean towards slightly warm with elevated treble and sub-bass, an even and natural mid-range response, with reduced mid-bass. The HiFiMan RE800, Brainwavz B400, and thinksound On2 offer examples of signatures I enjoy.


  • Driver: Five Knowles Balanced Armatures
  • Frequency Response: 8Hz-40kHz
  • Sensitivity: 110dB/1mW
  • Impedance: 16ohm

Packaging and Accessories:

The D5’s packaging quite pleasant, finding a nice balance between overly minimalist and wasteful. The exterior sheath is adorned with a cloudy sky motif. On the front is an image of the D5 crafted from dots, I suspect to simulate a constellation. This makes me question the decision to go with a cloudy sky instead of a night sky for the background, but it still looks nice regardless. Below the dotted D5 is the name of the earphone, and to the left a “Hi-Res Audio” sticker. Flip to the rear and you have a few bulletpointed features, specifications, and contact information for Astrotec.

Removing the sheath you’re greeted to a matte black monolith of a box with only “astrotec” printed on the front in silver foil lettering. Opening the magnetically sealed lid reveals a cardboard insert. On one side is Astrotec branding, the other a number of instructions such as how to wear the D5, what the blue and red markings mean, and how to use the foam tips. Removing the insert reveals a massive waterproof, shock resistant carrying case fitted with a pressure regulating air valve. Large and small tips are nestled in a protective layer of foam protecting the case which holds all the rest of the accessories. In all you get:

  • Delphinus 5 earphones
  • Braided MMCX cable
  • Carrying case
  • Single flange silicone ear tips (s/m/l)
  • Foam tips (m/l)
  • Airplane adapter
  • Carabiner

In all this is a pretty nice kit. The case is of excellent quality and plenty large enough to hold the earphones and possibly a small DAC, though that also means it’s not comfortably pocket-able. The included tips are quality items, especially the medium sized foam tips which feel like a more dense, grippy version of tips made by Comply. Not sure who supplied them, but they’re a great addition.

Build, Comfort, and Isolation:

The D5’s build quality is quite impressive. The aluminum bodies are nicely cut and quite angular on the exterior, but where it touches your ear they have been rounded and smoothed. The two halves of the shells fit together well with a flush MMCX receptacle protruding from at angle out the top. The nozzles are not a separate piece glued in place, but part of the inner half of the shell. You won’t have to worry about them snapping off accidentally. You also won’t have to worry about dirt or debris falling inside as the openings are protected by a fine steel filter that you can just barely see two sound outputs through.

The cable looks to be a straight copper unit with a fairly loose braid below the y-split, changing over to a two strand twist above leading to the ear pieces. The sheath is somewhat stiff with some memory retention when bent. It reminds me a lot actually of the cable used on the PlusSound EXO-BT Bluetooth module. It looks and feels like a high quality unit. Strain relief is decent overall. At the straight jack it is loosely around the cable with a millimeter or so of play to either side. It is quite soft though, offering good support to the cable should it bend that far. The y-split is a small metal cylinder, free of strain relief. Instead you get a useful chin cinch that stays in place when in use, tucked under your chin. Up at the ear pieces you find some preformed ear guides doubling as strain relief. They’re intelligently curved and comfortable, keeping the cable neatly behind the ear. My only complaint about this cable are the bodied of the MMCX plugs themselves. They are just a fraction too large, so when plugged in they rub against the housing ever so slightly. I suppose you could look at this as a positive since it doesn’t affect connection stability, and keeps the cable from spinning freely, something that can be quite bothersome.

Comfort is actually outstanding, much better than I was expecting. When I first saw the D5 in pictures, I was expecting that angular design to carry over to the ear-facing side of the housings, like it does on Campfire Audio’s Polaris. Given the D5 is quite rectangular in shape, I was expecting some mild hot spots here and there. Not the case. Astrotec did an outstanding job designing this shell, rounding out the inside of the shell so as to ensure only smooth surfaces touched the ear. With the right tips in place, I can wear these for hours. They’re quite light and ergonomic.

Since the D5 uses sealed metal shells, isolation is expectedly good. Maybe not as impressive as something with a deeper insertion, but well above when I expect from vented, dynamic driver based earphones or hybrids. Toss on those included foam tips and you’ve got yourself a proper, high end commuter headphone. Looks good, sounds good, feels good, and it abolishes outside noise. Win.


Tips: I have nothing against the stock tips and can see them working really well for most. I used Spintfit CP100 tips for the duration of this review because I’m horribly shallow; they looked great paired with the D5. They also allowed a very consistent seal and didn’t alter the signature much from the stock tips (slightly more low end).

Treble on the D5 is smooth and vibrant. There is a small peak at 7k that gives the presentation air and sparkle. It leads into a fairly smooth but significant roll off afterwards. Lower treble is only a few dB less prominent retaining impressive clarity and detail throughout the treble regions and down into the midrange. Tossing on Michael Jackson’s “P.Y.T. (Pretty Young Thing)” and Gramatik’s “Bluestep”, you can hear the cymbal work throughout has solid presence without being overbearing thanks to that roll off, and is supported by some snappy attack and decay giving the upper ranges a nimble feel.

The D5’s midrange is very prominent with a small lift in the upper mids that helps improve clarity and gives them a very natural timbre. Running through Porcupine Tree’s acoustic heavy “Pure Narcotic” shows off the D5’s beautiful timbre quite effectively. “Gross Magik” by Tobacco is very mid-forward and gritty. Contrasting it with the super smooth “Undefined” by Culprate shows off how nuanced and versatile the D5’s midrange can be, able to accurately portray tracks that are overtly varied in their style and presentation.

Astrotec Delphinus5

When it comes to the low end the D5 is very reserved. Sub-bass extension is quite good with only a mild roll-off, but there isn’t a ton of visceral feedback. Not unexpected given this is a BA-only earphone with a focus on the mid-range. Texture and speed are excellent with the D5 easily outputting the grungy, grimy textures you’ll find on tracks from The Prodigy, such as “Omen” from the Invaders Must Die album. It all feels very nimble and accurate doing a great job of supporting a track. These won’t please a bass head, but someone looking for something with a more neutral-leaning signature should be more than pleased.

All of this resides within what I found to be an expansive sound stage that is rife with layers and depth. The D5 is one of those earphones that constantly has me pulling one ear piece out thinking I heard a knock at the door, or someone call me from another room over. The base presentation puts you front row, but it can toss sounds well off into the distance like few other earphones I’ve tried. I found it really immersive with games such as Dirt Rally where the quality sound design really shines through the D5. Running a stage in cockpit view, the way stones ping and bounce around in the wheel wells is tops.

Select Comparisons (volumes matched with Dayton Audio iMM-6):

Brainwavz B400: The D5 and B400 are similar enough that I consider the D5 a near direct upgrade, high praise given the B400 has been my personal favorite earphone since I reviewed them in October 2017. I say near direct upgrade because while there are a lot of similarities to their sound, they both have Knowles drivers after all, their frequency balance is different. The B400 is slightly more with more bass. It’s treble extends more naturally than the D5’s but there is less emphasis. This gives the B40 a warmer, bassier feel to it. The B400’s bass is slightly more impactful and visceral too. The D5 is slightly more detailed and has a larger sound stage. Imaging is amazing on both, but the D5 somehow manages to impress even more when it comes to layering and separation. The D5 is essentially a less warm, more neutral B400 with a larger sound stage and further improved technical ability.

When it comes to build there is really no comparison. The B400’s 3D printed housing simply aren’t built to last like the D5’s are, though they are exceptionally comfortable. Isolation is slightly better on the B400. Comfort is mixed. The B400 fits my left ear better, but the D5 fits my right ear more comfortably. Nor sure why. The upgraded Frosty cable my B400 is equipped with is one of my favorite cables on the market for it’s combination of a good price (45 USD), build, and other positive qualities. It doesn’t look quite as premium as the D5’s cable, but it is more flexible and completely memory resistant. I really like Brainwavz’s perfectly implemented memory wire, but it just doesn’t feel as nice as the D5’s preformed guides.

Fidue A85 Virgo: The A85 has a slightly mid-forward signature that compliments the D5’s balanced, neutral leaning sound quite well. The A85 has better treble extension with similar detail output. The mid-range is more forward on the A85 but lacks the micro-detail and timbre accuracy of the D5. When it comes to bass I find the D5’s balanced armatures more competent; similar extension, faster and more controlled with more impact. The A85 has a similarly large sound stage but sets you further back from the music. It doesn’t seem to have the same level of depth as the D5, nor does it layer quite as well. Imaging is quite accurate on both.

Both earphones are beautifully constructed, taking very different approaches to their designs. The Virgo has an organic shape with flowing lines versus the D5 which has a more angular, geometric take on earphone. The Virgo’s paint is more durable but makes the shells look somewhat plastic. The D5’s cable feels like a higher quality item with it’s braided design. The Virgo’s cable sheath is quite similar to those found on more budget oriented products, but slightly thicker. The Virgo’s preformed ear guides are more aggressive and stable, but the broad curve doesn’t let it sit quite as naturally behind the ear. Fit and comfort goes to the Virgo which is more alike the shape of the outer ear. Isolation is better on the D5 as a result of the Virgo’s shallower fit and ample ventilation for the hybrid setup inside.

Campfire Audio Polaris:The Polaris’ v-shaped signature is quite apparent beside the D5. The Polaris’ low end shows significantly more authority thanks to it’s dynamic driver. Depth and impact are greater with the Polaris providing a more visceral experience. It also comes across slightly more textured and nearly as quick. The D5’s mid-range is significantly more prominent. It shows more body and weight giving it a more realistic presentation. I especially found it’s timbre more accurate. The Polaris has always sounded a little off. Live instruments always sound a bit lighter and brighter than they should. Still excellent, but not quite right. Treble on the Polaris is leaner and better extended with more shimmer and sparkle to it. It’s a little aggressive though, with the D5 finding a better balance of detail, clarity, and listenability. The D5’s sound stage is larger and much more even in size compared to the Polaris which is very spacious but lacking depth. It also shows off similarly accurate imaging with even more impressive layering and separation. The Polaris is a very technically adept v-shaped earphone. The D5 is a very technically adept neutral earphone.

In terms of build the two are a wash. The Polaris has ever so slightly better fit and finish, but both suffer from rapid paint wear on the angled corners. The Polaris also has a 3D printed nozzle versus the D5’s which is part of the inner half of the metal shell and not a separate part. Both cables are excellent. The Polaris’ is more flexible and better relieved but the memory wire loses shape and requires constant readjustment. The D5’s cable looks and feel more premium but is stiffer and retains some memory of bends and kinks. When it comes to comfort, I found them equally good, though I suspect those who found the Polaris uncomfortable will be much more at home with the D5 which is smaller and less angular. Isolation is no comparison. D5 all the way. The Polaris has fairly mediocre isolation. It also has an exterior vent that picks up and exaggerates even the slightest of breezes flowing past.

Final Thoughts:

Reviewing luxury items like the Delphinus 5 can be challenging because everyone’s concept of value is different. Dropping 500 USD on an earphone may seem asinine to some, while to other this is a mere mid-range offering that doesn’t warrant consideration. I spend the vast majority of my time with high performance to dollar budget gear, yet I feel the D5 is well worth the money and a great value. It takes nearly everything I love about the Brainwavz B400, an earphone that was previously my favorite, and makes it that much better.

It isn’t just a pretty face. It’s a complete package with great build quality, a fleshed out accessory kit, outstanding comfort, and a clear, detailed neutral-leaning signature that finds an addictive balance between being fun and analytic. My only real complaint is the upper treble rolloff, and that hardly ever cropped up as an issue in any of my testing, or personal listening time of which this took up a lot. This earphone easily goes head-to-head with other premium offerings I have on hand in terms of technical ability, and for my personal preferences, is near perfect in it’s signature. This is the sort of experience I would be looking for when moving on and up from budget friendly gear, and is absolutely worth checking out.

Thanks for reading!

– B9Scrambler

***** ***** ***** ***** *****

Some Test Tunes:

Aesop Rock – The Impossible Kid (Album)

Hail Mary Mallon – Are You Going to Eat That? (Album)

King Crimson – Lark’s Tongues in Aspic (Album)

King Crimson – Starless and Bible Black (Track)

Supertramp – Crime of the Century (Album)

Infected Mushroom – Legend of the Black Shawarma (Album)

Gorillaz – Plastic Beach (Album)

Massive Attack – Mezzanine (Album)

Fleetwood Mac – Rumors (Album)

Run the Jewels – Run the Jewels (Album)

The Prodigy – The Day is My Enemy (Album)

Tobacco – F****d Up Friends (Album)

Felt – Felt 2 (A Tribute to Lisa Bonet) (Album)

Michael Jackson – Thriller (Album)

The Crystal Method – Grace (feat. LeAnn Rimes) (Track)

Jidenna – Long Live the Chief (Track)

Skrillex – Ragga Bomb (Track)

Big Grams – Run for Your Life (Track)

Funkadelic – Maggot Brain (Track)

Aesop Rock – Fishtales (Track)

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