Aurisonics ASG-2.5 Generic Fit Digital-Hybrid In-Ear Monitors in Polished Red

General Information

Legendary Hybrid, Noise Isolating In-Ear Headphones. The ASG-2.5 has an unrivalled soundstage and legendary performance. The sound is incredibly raw, visceral, and energetic with a massive bass response that you can tune. Be prepared for music that will move you.

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Pros: Quality and quantity of bass, adjustable bass port renders EQ redundant for most people, classic Aurisonics vocals, nice dash of clarity up top
Cons: Potentially too much bass for some, fully opening bass port may start World War 3 if used in politically unstable countries
Aurisonics ASG 2.5 – initial impressions
I have recently picked a pair of the Aurisonics ASG-2.5 in one of the many closeout sales that are going on due to their acquisition/merger with Fender, and these are my initial impressions after burn-in and a solid week of listening. I’m still pretty new to this whole review/impressions thing, so please take it all with a pinch of salt – YMMV.
About me: newly minted audiophile, late 30s, long time music fan and aspiring to be a reasonably inept drummer. Listen to at least 2 hours of music a day on my commute to work – prefer IEMs for out and about, and a large pair of headphones when I have the house to myself and a glass in my hand. Recently started converting my library to FLAC and 320kbps MP3, and do most of my other listening through Spotify or Tidal HiFi. I am a fan of rock, acoustic (apart from folk) and sarcasm. Oh yeah, and a small amount of electronica. Not a basshead, but I do love a sound with some body to it.
The packaging is simple but sophisticated. The box itself is a small rectangle, which contains the IEMs in a nice presentation window, and everything else in the lower half of the box inside a small Otterbox style hard case which is designed to keep your earphones safe from water, heavy impacts and the sudden outbreak of World War 3. Compared to other packaging I have seen at this price point (and the one below), this is nothing special, but does lay out the contents and info in a nice and classy looking manner.
Build quality and ergonomics
The 2.5 is an all-plastic/acrylic affair, built using Aurisonics patented “Digital Hybrid Technology” process for an almost custom fit. The manufacturer claim to have scanned the ear geometry of thousands of people, and 3D print the IEM shells to provide a fit that is as close to a genuine custom-IEM as possible for 95% of the population. In practice, this holds true (at least for me) – the large plastic shells map to the contours of my ear very well and sit comfortably in place for hours on end as if they weren’t even there. Another benefit of the custom shape is the high level of noise attenuation that comes along with it – these are very good at blocking out train noise, oncoming traffic, screaming children and semi-automatic gunfire (the last one is a guess, but probably an accurate one). The overall impression is one of comfort and quality – despite the all plastic manufacture, these IEMs do give off the impression of being built to last, and survive the bumps and bruises of day to day use with ease.
As a custom shape, these are a large set of in-ears, protruding a little way out of the ear canal even with the snuggest of fits. As mentioned, this never feels any less than 100% comfortable, but may stop you wearing them to sleep in or slip in unnoticed when pretending to listen to another childhood war story from Great-Uncle Albert at the family Christmas dinner.
Sound quality
Test gear
LG G Flex 2 (with and without Brainwavz AP001 mini-amp)
Sansa Clip+ (Rockboxed, amped as above)
Microsoft Surface Pro 2 (straight from the output jack)
Test tracks (mainly 320kbps MP3 or FLAC/Tidal HiFi):
Nathaniel Rateliff & The Night Sweats – S.O.B. / Wasting Time
Blackberry Smoke – The Whipporwill (album)
Slash – Shadow Life / Bad Rain (my reference tracks for bass impact and attack, guitar “crunch”)
Slash & Beth Hart – Mother Maria (vocal tone)
Richie Kotzen – Come On Free (bass tone)
Otis Redding – various
Elvis – various
Leon Bridges – Coming Home (album)
Foy Vance – various
Blues Traveler
Daft Punk – Random Access Memories (album)
Sigma - various
Rudimental – various
Rodrigo y Gabriela – various
Mavis Staples – Livin’ On A High Note
Bass port settings used
The ASG-2.5 comes with an adjustable bass port, tuned with a tiny screwdriver via a screw in the middle of the main housing to alter the amount of air let in via a mechanical vent on the side of the shell. The Aurisonics “house sound” for their 1 and 2 series earphones is famously bassy in the low end, and this IEM is no exception. In fact, by reputation alone, the ASG 2.5 is known as one of the all-time great bass monsters of the IEM scene. More on the bass later on (might as well save the best till last), but in terms of this review, I have tried the 2.5 with bass ports fully closed, ¼ open and fully open. After placing my head back on my shoulders from my attempt at listening to the beast in full flow (imagine the famous exploding head scene from Scanners), I have settled on ¼ open as my default, so the below impressions are based on that setting unless otherwise stated. On a serious note, anyone capable of listening to the bass roar that this piece of engineering genius spits out at full throttle without a pair of titanium ear canals is probably either deaf or would sleep through a space shuttle launch.
The ASG-2.5 is built on a hybrid design, with one huge 14.2mm dynamic driver providing the low end, and one of Aurisonics patented HDBA tweeter arrays (basically two balanced armatures) providing the high notes. In practice, this works very well. The highs on this earphone are more pronounced than you would imagine for a bass-driven IEM, and provide a nice level of clarity and crispness to proceedings up top, cutting through the overall sound signature nicely. These could never be described as a treble heavy listening experience, and the tone of the highs is very smooth and feels slightly rolled off at the higher end of the frequency spectrum. In practice, this provides a nice level of detail without ever coming across as harsh, while remaining unfatiguing for extended periods of use. Comments on this IEM have mentioned the treble as being slightly recessed compared to the mids and bass – while this is true to an extent, with the right tips, the detail and tone is exceptionally sweet and pleasant on the ear. In terms of “air” and splash, the balanced armatures do manage to give a nice sense of space to the more ethereal passages of music played, with cymbals sounding nicely metallic but not too etched or tizzy as the notes decay. My personal preference is for a smoother treble sound (as long as the detail is still there), and these fit the bill excellently.
Another thing Aurisonics are famous for is the mid-centricity of their IEM offerings (the founder Dale Lott being a singer in his previous career probably has more than a little to do with that). I am happy to say that the 2.5 is no exception, with a fantastic tone and timbre being imparted to vocals (female vocals seem to particularly shine, possibly due to the extra “thickness” imparted by the lower end of the soundscape). The sound is forward and presented in a very natural, realistic manner, with the micro-details present in any vocal passages being noticeable in the back of your mind (catching of breath by a singer, slight rasp in their voice on a particular phrase), rather than being smeared across the front of the viewing landscape like they might be in a more “analytical” listening device. Like the highs, the mids are more about tone and musicality than crispness, and the whole listening experience benefits from it as a result. In fact, musical is a great word to use to describe the aural experience these IEMs offer – rarely have I heard something that is able to reveal the detail of a recording so well while still holding onto its “soul” at the same time. The overall tone is slightly thicker than neutral, giving superb weight to heavy guitar lines if you are listening to rock music, and an “in the room” feeling when you are listening to more laid back acoustica. Something like Mother Maria by Slash and Beth Hart or any Alison Krauss track you care to name will both highlight some of the unheralded beauty of these earphones, presenting vocals that you believe are being sung right in front of you, and have the power to genuinely stir some emotion in the heart of the listener.
If you are reading this review, this is the section you came to look at. I might as well have gone all “All work and no play makes Jack a dull boy” two hundred times in the section above (if you think I have lost my mind, please watch The Shining with Jack Nicholson to see what I mean) and you would still be reading this, so I’ll get to the point: Bass. Slamming bass. All the bass. Bass that sets off earthquakes. Bass that Chuck Norris HIMSELF is scared of. That’s the sort of bass that these things are capable of producing. With the bass ports set to fully open, the low end sound rolls in like a tidal wave, an entire ocean of mid-bass being supported by sub-bass reaching down to the ocean floor and beyond. At that level, the bass takes over so much of the sound signature that it is strictly basshead-only territory, so my comments are based on a more sedate ¼ open port, which still produces more than enough slam and sub-bass rumble to put a dirty great smile across the face of most music fans without even trying. The stated frequency range of these IEMs is 8-24000 Hz or thereabouts, and that is quite believable. Something like Daft Punk comes through with an authority and endless reserve of depth that is quite staggering for an in ear solution, and can sometimes feel like you have a subwoofer strapped directly to your earlobe. All the power does come with control, however, so the bass never feels like it is riding roughshod over a track. To use an analogy I have mentioned before on Head-Fi, this very much reminds me of a heavyweight boxer working a heavy bag - imposing presence, coupled with a palpable sense of power and precision rather than uncontrolled aggression that leaves you under no illusions that each blow is landing exactly where it is supposed to be. Along with control, the general tone and timbre of the bass deserves a special mention - all the power sacrifices none of the detail, so with ports opened slightly, you get the wonderful rasp and detail of the basswork on some Slash tracks coupled with the slam of the kick drum hits flexing your eardrum in and out without ever blending into each other or overpowering the rest of the sound. The additional bass does come with a tradeoff in terms of separation, however - as the bass ratchets up, each element gets that little bit thicker, so the band start standing closer and closer together in your head as the bass ramps up.
Difference between the port settings
The sound of the 2.5 is really defined by how much you are willing to let the bass port open - with the bass ports fully closed, the sound can almost seem neutral for tracks that don't have a heavy bass presence, with the big 14.2mm driver only firing up when the track has bass in the mix. This is the closest you will come using this IEM to an "audiophile" sound, although there is still a warm tone and slight thickness to the mids and highs which pushes this towards musical rather than analytical. With the bass port 1/4 open (my preference), the bass presence is there in force, but never bleeds into the mids or highs, so well mastered bass tracks will thump along with a thundering bass presence underpinning everything, but the driver will still let the mids and highs shine when it isn't needed. The 1/4 open setting also adds a little thickness to guitar and vocal tones as the bass "edges" of these sounds are reinforced by the massive driver thickening them up, adding to the overall warmness. Fully opening the port leaves everything awash in thick, pounding bass - the mids and highs still cut through the mix without much (if any) bleed, so if that's your thing, these must be close to the best solution out there along with some of the Sony or JVC lineup to really blend some braincells in style.
The 2.5, in common with other ASG models, does have a nice broad sounstage, with good 3D imaging and separation of instruments at the lower end of the bass settings. As mentioned above, the more bass you introduce, the thicker the edge of each instrument gets, so it becomes more difficult to pick them apart in the wall of sound, but as the detail is still there, it is still possible if you listen hard. At minimum setting, the positioning of each instrument is readily apparent, with a good "small venue" vibe being given to the listener rather than a quiet studio experience. The ASG range was built primarily for musicians and on-stage use, and this reflects in the presentation of sound.
The 2.5s can be driven quite easily direct from my phone or Clip+, so amping will only need to be considered if you want to extract maximum detail and "potential" out of these IEMs. Reading other comments on here, those of you with higher end amping solutions will experience a slightly more "audiophile" experience, but given the general all round quality of the music presented using "lower end" sources, I haven't felt like I am missing anything yet.
This will be updated in due course, but as the sonic presentation of the 2.5 is aimed at the basshead in everyone and I don't have much experience with truly basshead sound sources, I am leaving this a little while to form some more concrete opinions before offering any comparisons.
Overall conclusion
One of the key words used by Aurisonics to describe these IEMs is "visceral", and that, in a nutshell, sums these up nicely. They provide a musical, powerful sound, packed full of emotion and backed up with detail and quality from the low end right up to the slightly less prominent highs. Kudos to the design team for creating something so unashamedly bonkers but at the same time satisfying - as I mention at the start of this review, I am by no means a basshead, but the genuine pleasure experienced listening to some vocal and rock tracks through these (big) beauties is making me reach for them more and more often, as it is almost addictive. No IEM I have heard yet is without flaw, and the 2.5 is no different - purists may think the bass is still overkill on the lowest settings, and detail fans may ask for more crispness, but they would be missing the point of this IEM: to bring out the enjoyment and power (emotional AND physical) of music, leaving you smiling at the end of each listening session. For anyone who gets a chance to try these out, please do so - it will open your ears to a whole new way of listening to things!
Excellent review. Thanks
Pros: FCUK ME kinda bass. Beyond epic bass depth. Stupendous Bass power.
Cons: You had better be a bass lover.
Aurisonics ASG-2.5 Quick Review
Thanks to Hifiheadphones for the loaner.
Full review here
Brief:  OMG ALL OF DA BASS!!!!!
Price: US$700 or circa £451 or more if want a diff finish on them.
Specification:  Driver: Precision Dynamic 14.2mm + 2 custom-tuned, next generation tweeters, Frequency response: 8Hz – 25kHz, Impedance: 41 ohm +/- 10% @ 1kHz, Sensitivity: 123dB @1mW, Passive noise attenuation: NRR 22db, Construction: 3D printed, Digital Hybrid Technology (DHT)™ shell fits 95% of ears like a custom (Hybrid custom/universal fit derived from thousands of ears scanned… and counting)., Cable: Detachable silver-plated low oxygen copper cable
Accessories:  Shock/Dust/Waterproof case.  Cleaning tool.  Tips.  Valve adjusting tool.
Build Quality:  It would appear to be excellent.
Isolation:  Meh.  For an IEM it’s passable but that’s what happens with dynamics.  They need air to move and with the venting port you do loose some isolation.  So not Tube worthy but would easily do for normal out and about stuff.  Still probably enough to get you run over too if your not looking where you’re going.
Comfort/Fit:  There is no mistaking they are huge but they are sculpted so that they fit me easily, effortlessly and perfectly comfortably.  Stuck on Comply’s ‘cause I’m lazy and that was me.  Of course if you turn the bass up I found it moved so much air is was physically uncomfortable.
Aesthetics:  The look nice.  Nothing particularly special, though if you are suitably rich and chavy you could have them made in 24k gold for just an extra US$400.  Mind you the pics of the brushed nickel look quite nice. 
Sound:  When you have the bass dial at min, these are pretty good, rather even ish balanced.  Bit of a W shape going on but nothing wildly out of step with anything else and the quality is what you would general think to expect from an upper end IEM.  The BA’s doing the tweeter and presumably the mids too are nice.  They are clean, tonally quite neutral and nicely detailed.  They are very pleasing in every matter you think to ask of them.  Even the extension is pretty good and BA’s traditionally don’t do so well at that.  So good, nothing magical but a very good solid contender for your money.    Then that bass.  The spec says 8Hz.  I think its lying, with the quantity of air the humongous 14.2 mm driver spits out its more like 2Hz.  (Okay not that I could hear 2Hz) the depth is stupid.  It extends so far and bugger me it just goes so effortlessly, oh my god it’s just amazeballs lunacy!!!!  No seriously it is just insane, its comedy levels of bass and oh god the depth!!!  It’s mental.  Lol.  You know if you dad came home with a 5.1 set up and you took the sub and turned it all the way up?  You know where your mothers ornaments all start vibrating and walking about the mantle piece.  All the while you being shaken by the room that’s turned into a giant vibrator and you find yourself laughing like some giddy fool?  Yep, that.  Its nuts, completely off the wall.  While this is super-duper entertaining.  It’s just mad.  Now if you step away from bass centric stuff and put the bass to minimum it’s a rather capable high end IEM but it feels pointless to talk of its other talents.  If you buy this, you do so because you want bass that will blow you away, seriously just blow you away.  Slap on some chart type pop and its an orgasmic thrill machine.  Amazeballs mental.
Value:  Well it’s cheaper than buying 20k’s worth of Sub’s.
Pro’s:  FCUK ME kinda bass.  Beyond epic bass depth.  Stupendous Bass power.
Con’s:  You had better be a bass lover.

Pros: Soundstage, clarity paired with incredible bass impact, bass valve adjustmentsAurisonics ASG-2.5 Review Introduction Many thanks to for
Cons: large, can be uncomfortable for some, might be too much bass
Aurisonics ASG-2.5 Review
Many thanks to for providing me with a ASG2.5 for a week to review.
Aurisonics is a Nashville, Tennessee, US based company that produces mostly by hand and it shows. Aurisonics stands for Auris is latin for ear and Sonics is the practical application of sound. A nice name for an audio company. When a mastering engineer founds an audio company, audiophile ‘listen’ hah!! Fire up youtube and search for Dale Lott, he is the founder and CEO of Aurisonics and if you need to see someone standing behind his products - watch him. Check out the Aurisonics website, amazing read for sure.
 Manufacturer’s Specifications
  1. Type: in-ear
  2. Drivers Size: 14.2mm (dynamic driver)
  3. Drivers Type: 2 Balanced Armature custom tuned & 1 Dynamic
  4. Frequency Response: 8Hz to 25KHz
  5. Sensitivity: 123dB @1mW
  6. Impedance:  41 Ω
  7. Microphone sensitivity: 
  8. Maximum Input:  
  9. Weight with cable: ??g  
  10. Connector: 3.5mm single ended
  11. MSRP:  $699 - $1099
The ASG-2.5 are digital hybrid technology (2 tweeters and a large dynamic bass speaker) universal fit in-ears. They are also available as custom shelled versions.  These in-ears are handmade in the US (Nashville, TN) and have a tunable bass port. They come in different colors (and materials which affects the price). I had the polished red one but they are also available in polished black, brushed nickel and 24k gold. Cables are detachable and connected with a 2 pin cable. So you can upgrade the cables at  later stage or replace them should they break. The cable has a memory wire on the top part so once in place it stays in place.


The polished red ones look gorgeous, you can see the internals through them - love it. Makes it look very cool. They are worn over the ear. They are shaped like customs. Orisons claims that they will fit 95% of all ears very well (like a custom). I must say that this was true for my left ear but the right one had a few issues.

Build quality

If you have ever seen a video with the founder of Aurisonics Dale Lott - you know that these are rock solid in-ears build to last. His experience is in producing military spec products so everything you get is sturdy and will last. 


While Aurisonic claims that they will fit like customs for 95% of the population (as far as they scanned ears so far) I can only confirm that half. LOL. The ASG2.5 fit perfect in my left ear, the right one always took a lot of adjustments to get “right” - once in, they were comfortable for me and I forgot I had them on pretty soon. However, be careful as they are quite large, there is a chance they rub on one part of your ear and that can create discomfort. 

Supplied accessories

Packaging is rather small and functional. A very nice sturdy shock, dust and waterproof carry case (like a SKB or Pelican case) is included, as well as a cleaning tool and a screwdriver for the bass port adjustments (called valve adjustment). The tips are custom made for Aurisonics and are trademarked SureSeal tips. I wish there were a few more sizes and shapes in the box though, 5 pairs for a $699 in-ear is a bit on the skimpish side. 
I received a burned in demo piece. I put them on and thought - holy moly the bass. then holy moly, the soundstage, and then finally, holy moly the clarity. I really liked the sound quality of these in ears. Here are the details…


The best bass I have heard in any in-ear. Period. Since I had a demo piece I was listening to it for an hour and thought to myself, my goodness, the bass is really amazing. Then I remembered they have the adjustable bass ports and thought, ah, ok, they are probably on full blast, now let me dial down the bass and see how they sound with less bass. Then I realized that the bass valve was already on the lowest setting. I consider myself as a borderline basshead but what these headphones can produce in bass is beyond ANYTHING I thought would be possible with in ears. Amazing. They go low, very low. And they are not bloated or flabby. They really mimic as subwoofer. For me, closed valve (or on the lowest bass setting) was perfect. If opened then only by the tiniest of fractions, otherwise the bass was just too much for me unless you want a real party in your head. Bass lovers, this is your in-ear. If you leave it in the normal setting you should be happy with them unless you appreciate really subwoofer like - earth shattering bass that these things can provide.…


Vocals sound unbelievable good. With so much bass you usually have something that sounds recessed or distant, as it’s simply overpowering some other frequency ranges and mostly the mids. Not so with the ASG-2.5 male and female vocals sound nice and forward.


Not harsh, no sibilance. A bit laid back giving you a fatigue free listening experience. The treble might be a bit recessed - though you do hear details a plenty. 

 Sound Stage and instruments separations

This in-ear is a soundstage master. Since it’s supposed to be used as well as a stage monitor or mix monitor - it makes sense to have great accuracy in placing instruments in space and hearing the soundstage as it is in real life.  
Pros & Cons


  1. Sound quality 
  2. Soundstage
  3. high quality replaceable cable 
  4. high build quality, built to last, build to withstand rockstar-abuse 
  5. the best bass you can get

  1. quite large, so make sure it fits or get them as customs
  2. comfort (option to go custom shell with those)
  3. pricey

  1. Comfort                       7/10
  2. Sound Quality             9/10
  3. Design                        7/10
  4. Durability                    9/10
  5. Value for Money         7/10
They are amazing and I honestly didn’t want to return them to (again many thanks for letting me review them). But then I had to make the decision between them and the HE-560 and sorry the over ear won. I am still debating of getting them as I simply cannot forget the bass and this amazing subwoofer like rumble.
If you think of buying them, think about getting them as customs, Aurisonics does offer them in universal fit (like in this review) and as custom shelled in-ears. I had some fit issues in my right ear and they were for me a bit finicky to get in. SO if you need to take them on and off a lot this could be a deal breaker for you. 
Disclaimer:  I have not been paid or got any kind of freebie for this review - sadly I had to return the demo set back though I really didn’t want to— they are that good. 


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