Audeze iSINE 20
Mike Piskor 2017

Audeze iSINE 20 Review

The Audeze iSINE 20 is the second in the company’s series of open-back planar magnetic in-ear monitors and a step up on the iSINE 10. It is priced at $599.

Disclaimer: The Audeze iSINE 20 sent to us is a sample in exchange for our honest opinion. We thank the team at Audeze for giving us this opportunity. 

To read more about Audeze products we have reviewed on Headfonics click here.

Note, this review follows our new scoring guidelines for 2021 which you can read up on here.

Audeze iSINE 20
Audeze iSINE 20
Audeze once again proves it is at the forefront of modern audio and has paved the first portable Planar highway for everyone else to abide by. They seem to have played this one safe with the treble experience: neither offering too much or too little, not too much in the way of dynamics, and not boring in terms of engagement factor in a physical sense.
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Leave it to Audeze to once again transform the landscape of Audiophilia. Hard to believe that just a few years ago, we all dreamed of Planar portables. Now a reality with the Sine on-ear and now the iSINE inner-ear series, we’ve not much to dream about anymore.

For the first run of technology into the portable Planar universe of headphones, Audeze has laid the foundation for what I am sure is a barrage of fantastic portables to come in our near future.

The Design

Eye Catching

Well, you either love it or hate it. Audeze’s design of the iSINE 20 will certainly turn heads and shift eyes in your direction when spotted, I think that much is vividly clear.

I can’t say the design is lacking in appearance because I think I am in the minority here and feel it is very attractive. It does what it was intended with its intense and eye-catching appeal.

Visual Cues

In my travels, I’ve not been asked about a product so often when out and about. So many questions about what the hell is inside my ear, which leads to conversations about Hifi audio nearly every time someone inquires.

The odd choice of the iSINE 20 web-looking design intended, at least I think, to recapture the visual cues of Audeze’s older LCD series was admirable and well done. It screams Audeze and pretty much all Audiophiles can spot it a mile away.


They’ve chosen the same angle used for connectors as found in the older LCD series as well, which I do not think have ever been used inside an IEM design before anywhere that I can recall. It works well for the most part.

I think I’d not prefer that slightly forward angle to the entryway to the IEM housing itself, as the cable has some bunching up issues now and then, especially when I ride my electric scooter and the cable insists on adhering itself to a place on my chest that I am not fond of. Normal down-style IEM cables do not have this problem.

Audeze iSINE 20

The Design “works”

But, I digress. It is not felt nor even a minor issue when walking or sitting so I won’t take points off just because the wind forces the cable to bunch up when using a mode of transportation hardly anyone else uses.

Either way, Audeze paired with Designworks (A BMW Group Company) for all of the implementations of the iSINE 20. I think their work paid off, this one made waves in the community before the product was ever heard by anyone. All it took was a prototype image release to the audio community and the rest was history.

An Important Tech Quote

“Miniaturizing Planar drivers is no small feat. The new iSINE Series barely weighs 20 grams, contains all our exclusive patented technology including power enhancing Fluxor Magnets that nearly double the magnetic driving force on our large, ultra-thin diaphragms with patented Uniforce voice-coil technology that delivers the most accurate in-ear headphones experience ever. The distortion (THD) is less the 0.1% overall even at high volumes, an amazing achievement for in-ear headphone designs.” -Audeze

Sound Impressions

The Bass Quantity

Oh come now, this is why you came here to read this. We all know it, don’t deny that! Audeze is known for bass, what more needs to be said? In this case, the miniaturizing of a Planar driver has worked well for the case of quality, which is stellar, but quantity is a bit of an issue for anyone seeking excellent depth.

Truth be told, the iSINE 20 is a very smooth-sounding IEM down below that has good depth and quantity, but not enough to satisfy the inner bass head in me. Does that even matter? Nah, not really. Most listeners will enjoy it a lot, I am sure.

The problem I am having is entirely subjective: I expected a load of bass depth and quantity response on certain tracks but received something tamer, matured, and elegant. That is a wonderful thing most of the time and for most track listening experiences, but considering it is a Planar IEM, one would naturally think the physical quantity is potent.

Such is not the case. This iSINE 20 has good bass quantity, certainly not objectively lacking at all, at least not in my opinion. I may have expected something that the current Planar market simply doesn’t have anymore. IE: Planar’s with a lot of bass. It seems we’ve moved out of that field and into something more advanced, intellectual, smooth, and forgiving.

The Bass Quality

Truly, Audeze has achieved marvelous quality in the bass region and I haven’t the slightest negative comment, objective or even subjective, to toss into this review regarding it. Nope, not a single “even slightly negative” comment or thought crossed my mind from the first day I received it, to penning this review.

In terms of raw, physical quality, this iSINE 20 is sublime and sounds very similar to the way the LCD-3 Fazor portrays bass. Smooth, pure, lacking harsh impact, and a pleasure to listen to at all times. These are qualities that I’ve desired in my on-the-go experience since I converted to Audiophiliaism.

My goodness, I truly do not have any other IEM’s currently and officially on the market to compare to the level of quality and purity these iSINE 20’s offer. What’s more, they sound the same on my Cowon Plenue M as they do with my higher-end home desktop DAC and Amp combo. Stunning, to say the very least. If you want bass purity on the highest level for an IEM, this is for you.

Outside of the most expensive Custom CIEM’s that I’ve experienced, this is surely the only standard, non-custom IEM that houses purity on this level. The gap to the next best is significant, at least in my opinion.

Audeze iSINE 20


Oh, my. This is certainly an Audeze product! Gentle warmth, highly musical, but also absurdly clean. This, to me at least, feels again just like the LCD-3 in miniature form.

I hate to make that comparison, but swapping between them as fast as I can and through many A/B comparison sessions and I’ve come away feeling that the midrange and bass experience of the iSINE 20 and the LCD-3 are pretty similar in setup.

They are forward, but not overly so. They are rich and detailed, but not clinical or sharp, yet also house an audible level of musicality and slight warmth factor (a bloom effect, soft edges, easy to listen to indefinitely) that I find highly desirable. No, this iSINE 20 isn’t on the level of Audeze’s full-size models in terms of quality, but for an IEM, I think it is certainly top-shelf material.

Vocal Density

The iSINE 20 has a well-formed, dense feeling mids make the vocal experience highly enjoyable regardless of the genre of the track and I feel like that is a very difficult quality in audio to get right.

Quality itself seems much easier to obtain than an experience that is hefty, as well as clean. In my opinion, it takes a finely tuned, specific intent by the designer to produce a hefty-sounding Dynamic driver headphone.

With that in mind, only a few sets out there have really produced a Planar Magnetic-ish type of sound in a Dynamic driver, such as the Focal Elear, for example.

Getting that substance factor on a dynamics is so vividly rare, that I cannot really list more than a few sets in existence that do it well. 99.99% of all IEM’s are Dynamic driver coils, but now, we’ve something else on the table in the first.: REAL Planar Magnetic IEM’s in the form of the iSINE 20.

Upper Mids

I’ve found the iSINE 20 upper mids to be just a bit nasal. Subjectively, I can’t mark points off because I know this is the first attempt at this type of IEM.

Planar IEM’s are a new thing and to get it perfect on the first try is just an impossibility. But, they’ve still done admirably. Yes, I do think there is a little bit of an oddity sometimes when the track is highly energized by artists.

Sometimes, there is a little bit of a blur and blending of upper mids and treble, which I am not fond of. But once again, not a serious problem and one that I found to pop up rarely in my music experiences. So rare, in fact, that I can attribute it nominally to track quality and garbage mixing on tracks I might have thought were decently recorded.

Slight Smearing

Personally, I think it is a little of both: just a little nasalness and smearing of the line between the uppermost mids and lower treble, but also made a little worse by tracks that are prone to lots of singers belting tunes at once, or a highly energized track in general.

By that, I mean fast-paced tracks with a lot going on (untypical of 99% of most musical listening experiences one has) that combine to form shoulder shrug-worthy upper mids.

It isn’t a problem, but it is evident enough to cause a fuss with me when this or that track appears in my Playlist that houses this type of a messy recording, with too much going on, to differentiate what and where the vocalist placement is on the track.

The best example I can come up with is the group called Pentatonix, who insist on beatboxing and having 5 other vocalists all shouting at the same time. With tracks like that, some detail gets lost.

Audeze iSINE 20


I’d not call this a weak link in the chain, per se. I would call it leaving a bit to be desired. As the bass and midrange of the iSINE 20 are set up, so too does the treble follow a very good sense of smoothness, offering fatigue-free listening experiences. But, as with most very smooth-sounding headphones, they tend not to express abundantly sparkled or highly responsive treble.

What is there is very clean and clear, easily one of the best treble experiences in terms of raw clarity I’ve yet heard for an IEM. But, also what I consider overly reserved in quantity.

Don’t expect Noble or Hifiman HE-6 type of treble, do expect Audeze LCD style treble: a bit dry, lacking brightness and interesting texture.

Substance Factor

The iSINE 20 allotted treble is still very good in quality, no doubt. But as mentioned, quantity is an issue sometimes and I do find myself boosting the treble to achieve more substance.

Sadly, no middle-tier Planar in the full-size arena has achieved excellent treble outside of ye’ old Hifiman HE-500. So, I do not berate the iSINE 20 IEM for not achieving excellent treble as well. But, I stress: what is there, is very good and just shy of something I would consider excellent.

If it had more substance and quantity potential, all without sounding harsh or painful and retaining the stock smoothness factor, I’d score it higher for sure. This will certainly be tweaked in future models, undoubtedly.

I suspect all Audeze’s future Planar IEM’s will be more well-rounded from top to bottom. Here though and on the iSINE 20, the treble experience is smooth and tame, a bit too reserved, and requires a small boost up top to really create an even and smooth signature from the bass up to the top treble area.


Outside of very high-end custom IEM’s, I’ve not heard a soundstage as well-formed and vividly spacious as the iSINE 20. Everything is into the excellent tier, of height to width, depth of field to the separation of instruments and sound in general.

Yes, the iSINE 20 does sound staging very well. A natural presentation is so rare in IEM’s, especially so in Planar products. Yet, Audeze managed to get past that hurdle and fashion a very spacious sounding Planar IEM.

If you had asked me if this were likely to even be a thing at this time in 2015, I’d have raised an eyebrow and said this tech is far off, but very likely. Audeze hastened this faster than I thought they would, which is great news for future products.

They started off excellent and got over the bump in the road of the lacking staging properties in Planar headphones. Despite being an IEM, I really don’t care because now we can say there is an excellent Planar soundstage available: the iSINE 20.


The iSINE 20 physical slam factor is a non-issue and I consider this one of the smoother sounding IEM’s I’ve experienced with regard to bass and treble slam. Not The Smoothest, but certainly one of them.

Smooth Sounding

I have a pet peeve that revolves around wincing and shoulder shrugging, blinking, and jerking my head back when headphones exhibit harsh slam in a physical manner. I really can’t stand that and for the sake of the audio track and being accurate to it, I can’t call the iSINE 20 accurate in that sense.

It smooths most of the spectrum out for you and makes pretty much everything enjoyable, dimming the slam factor I know to be abundantly evident and ever-present on certain tracks I usually test with for this quality.


Is the iSINE 20boring and overly smooth? Absolutely not, this is an Audeze product and it still packs a little punch. I’d call it subjectively well-engaging and middle ground in that respect in terms of how much slam and kick is allotted.

It definitely subdues my very harsh tracks, so note that if you are after a clinical appeal in your dynamics, this isn’t the IEM for you. If you are after a relatively fatigue-free experience, I’d recommend you drop the cash for this and enjoy.

Audeze iSINE 20

Our Verdict

Audeze once again proves it is at the forefront of modern audio and has paved the first portable Planar highway for everyone else to abide by. They seem to have played this one safe with the treble experience: neither offering too much or too little, not too much in the way of dynamics, and not boring in terms of engagement factor in a physical sense.

Sure, the iSINE 20 design is wonky, but damned if they are not supremely comfortable when using the ear hook guides included in the package. Sometimes, I forget they are even in my ear. I often go for rides on my electric scooter while wearing them, winding down paths and enjoying without realizing I am wearing them.

I find it amazing that the nozzle placement, the iSINE 20 tips itself that goes into your ear canal, is so perfectly placed that it balances out the larger housing above it when used with the ear hook guides. It is quite a stellar IEM in almost every regard. From clarity to comfort, I don’t have much in the way that is negative to say on an objective level.

Subjectively, I wish they had implemented more treble quantity and perhaps more bass depth, or at the very least made sure to allow for better EQ response on the low end. I find myself managing a +6dB boost on the bass end and still wanting more as a bass head, as the bass does not alter as much as I would prefer when EQ’ed.

Beyond that, I expect…no, I demand Audeze continue onward with Planar IEM’s and portable Planar’s in general. They’ve proven now twice in a row that they are leading the pack in this Portable Planar game. I expect nothing but greatness from them in their future models.

Audeze iSINE 20 Specifications

Style In-ear, universal fit
Transducer type Planar magnetic, semi-open
Magnetic structure Fluxor
Magnet type High-grade neodymium
Diaphragm type Ultra-thin Uniforce
Transducer size 30mm
Maximum power handling 3W
Maximum SPL >120dB
Frequency response 10Hz – 50kHz
THD <0.1% @ 100dB
Impedance 24 ohms
Cable type non-microphonic
Dimension 31mm x 35mm
Weight 20g without cable

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