Pros: Tunable sound, noise cancelling in a TOTL headphone, high detail levels, dynamic sound, packed with unusual tech, bomb proof storage case and bags of accessories
Cons: Tuning capability less useful at the extremes, flimsy 2.5mm cable connectors, thin cables, onboard DAC not same quality as rest of package, slightly dry tinge to the sound
Price: £1170 (thomann.de)
I first came across the AKG N90Q at Canjam London 2017, nestled among the other AKG and Harman branded goodies on their booth. They looked interesting enough to pick up, and after a bit of investigation, something really interesting caught my attention – the TruNote technology. It’s not often you see a flagship piece of audio gear with a user selectable tuning, but it’s even less usual to see one that claims to change its tuning to sound best for your own particular hearing capability. Add to the that the even rarer addition of noise cancelling tech into the package (and half decent ANC tech at that), and it made for a very enjoyable 30 minutes playing with the various options and enjoying the sound. Sadly, the simple law of economics (read: lack of money trees growing in my home postcode) meant that I couldn’t take one home with me on the day, so I consigned this headphone to my lottery-win audio shopping list. Roll forward almost 12 months, and while cruising the classified ads on Head-Fi, I spotted a used pair at a very good price. Being a bit more fiscally fluid, I decided to the take the jump and pick up a pair to review. I’m glad to say I wasn’t disappointed.
For clarity, these were purchased by myself, and there has been no input from AKG or Harman in the review process, so all the opinions and observations are 100% my own, however misguided.
Unboxing and design
The N90Q come quite securely packed. In fact, they come packed securely enough to survive the onset of World War Three, in a multi-layered presentation box that weighs approximately 5 kilos (!), and comes apart in multiple layers. The initial impression is a very classy one, the outer box matching the colour palette of the headphones inside in a mix of matte and gloss black and metallic gold. There is also quite a prominent reminder that these headphones earn their Q-series moniker by being “inspired by Quincy Jones”.
The sides and back of the box have the usual technical breakdowns, and a bit of advertising copy of the vast array of features baked in to the headphones themselves, all laid on a black background with a shiny black sheet music underlay. It all looks pretty high end, with plenty of finesse. Sliding the initial shoebox style cover off the box, there is a hardboard black box underneath, held together with a small cardboard wraparound carrying some handwritten words of inspiration in gold ink from Quincy Jones himself.
Once you slide this off, another disassembly gets you into the meat of the package. The first thing you are confronted with is a gold and black headphone case, square in shape and made of solid metal. The edges are nicely rounded, and it carries a giant “Q” series logo on the front in metallic gold highlighting, along with the model number in smaller text alongside. Sliding the box out with the help of a crane and pulley system (it accounts for about 75% of the weight of the packaging) reveals a soft but high high quality leather carrying pouch in its own plastic bag, along with a charging cable for the headphones. Mining deeper still, the bottom layer of the box hold a user manual for all the onboard tech (and sporting another Quincy Jones quote), a 2-pin airplane adapter and a small cardboard box containing all the usual boring stuff like warranty etc. The accessories here are supremely well finished, with the leather pouch carrying an embossed logo, and the charging cable and adapter feeling well made and robust.
Laying the solid metal casing down on the table, it opens with a smooth motion in a clamshell format (i.e. the lid flips up from a central hinge on the back of the box). The hinges retain their position wherever you leave them, and don’t have a “lock” position as such, so rely on this ability to keep the lid shut when fully closed. This isn’t a portable case (it’s only really transportable if you are packing a holiday suitcase), so this is perfectly adequate for its intended purpose. The finishing is again high class, the rounded corners and immaculate finish giving the impression that this box may actually survive for longer than most of its owners.
Flipping the lid open finally reveals the headphones themselves, laid flat in the soft plastic cutout. The headphones fit snugly into the moulded cutout, with two rubber pincer strips in the box acting as guides for the headband when the cans are placed in, ensuring a solid and secure fit each time. The interior isn’t overly soft or padded, but given the incredibly solid exterior construction and the rubberised securing mechanism, I have no doubt this could probably survive a hefty blow from a bazooka shell without unduly damaging the contents inside.
Inside the arch of the headphones lays an oval shaped storage compartment, curiously only sporting the “N90” designation this time (perhaps Quincy doesn’t like “inspiring” packaging?) and a depiction of some audio cables. Popping the lid off reveals the various cables included with the N90 – one cloth cable for “traditional” 3.5mm sources, one Android cable for 3.5mm (with mic and control buttons) and a similar iDevice compatible mic cable. All three cables are well finished but surprisingly thin, given the relative sturdiness and luxury of the rest of the package. The headphone connector is single port (no balanced opportunity here), and uses a 2.5mm connector that fits flush with the shell of the headphones, rather than inserting more deeply into a recessed socket. That means that the connector will take the full brunt of any impact if you were to accidentally drop these or otherwise stress them, which seems a little flimsy given the great lengths they have gone to with the rest of the design. A recessed socket with some form of overlap to the actual body of the pin connector rather than just to the tip would have seemed like a much more durable solution here.
When the headphones are removed, the final few layers of the AKG onion are revealed: sitting in a recess underneath the headphone cups are a slimline AKG branded powerbank held in place by a small velcro strap (for recharging the headphones on the go via the included micro-USB cable) and a small micro USB cable connector. The connector was the biggest surprise, feeding through from the inside of the case to a well-hidden female micro-USB port on the back of the case itself. This actually allows either the powerbank or the headphones themselves to be plugged in to the connector inside the carry case and charged, allowing you to “top up” the charge in your cans without even having to take them out of the box. This level of attention to detail is what really sets the N90Q apart in my eyes, and is definitely a useful feature given that the headphones themselves will only work in “Active” mode, so once the batteries die, so does the sound. The powerbank is also functional and stylish enough to use as a day to day top-up device for your other USB powered electrical items, if you don’t want it to just sit there as backup.
Overall, the unboxing experience is as premium as anything I have purchased, and feels commensurate with an item costing well over £1000 at current retail prices. While the main carrying case is a little over the top in terms of build, it will serve as an eye-catching home-storage unit, with the smaller and more portable leather carrying bag being good enough to cover any day-to-day transport in style. Adding in the ridiculous amount of extras and design features like the branded power-bank, and I’d say that AKG got the experience just about right with these headphones, presenting something luxurious but ultimately functional.
The headphones themselves are a sturdily built affair, made of a combination of plastic, metal and pleather, and kitted out in the ubiquitous gold and black “statement” colours chosen for this model. The headphones aren’t huge, considering their over-ear status and the sheer amount of tech build in to the chassis, and keep a fairly low profile on the head. As an over-ear headphone, they do have a fair bit of width, but these certainly aren’t overly wide in comparison to things like the Campfire Audio Cascade or Focal Elear.
The headband has a nice contoured design, having an internal curve built to keep the band as flat as possible across the top of the head while still contouring to the shape of the skull. In other words, unless you are an extra from the Conehead movies, the N90Q should sit nice and flat on top of your head without any troublesome hotspots. Weight distribution is good, with the N90Q feeling lightweight enough to wear for multi-hour listening sessions without worrying about neck strain. This helps explain the choice of plastic in various sections of the headphones (like the cups), helping to keep the weight at a manageable level.
The earpads have a wide internal opening, and seal quite firmly against the side of the head. I have a larger than average skull, so for the smaller hat sizes out there, these should still sit quite nicely on your head without undue clamping pressure. The pads are soft and plump, and allow the drivers to get pretty close to the ear when seated correctly. The arms extend from the gold joints on the side of each headband section in set increments, marked with a number for ease of memory. The action is smooth and each increment clicks solidly into place, with no give or looseness. The headband itself isn’t overly thick, but does sit very nicely on the crown of the head, without generating any unwanted pressure or hotspots over extended wearing sessions.
Despite the lightness, the main cup assembly feels well made and sturdy, sharing a mix of plastic and metal. The faces of each cup have a corrugated section in a circular pattern around the circumference, as they are used to control the volume (right hand cup) and EQ settings (left hand cup) in a rotary fashion. Arrayed along the bottom of the metal cup frame are the power buttons (for the ANC), the TruNote / soundstage control button, the micro-USB charging port for charging the internal battery and using the onboard DAC and a 2.5mm port for the cable. The buttons are small, rounded and depress with a satisfying click, with a shallow but definite movement.
Overall, the build on display here is definitely commensurate with the hefty pricetag, with a mix of aesthetic touches and solid but refined construction that leaves the user in no doubt that these are a well put together piece of audio gear. Value for money is always a subjective matter when you are talking about a pair of headphones that cost over £1000, but all I can say here is AKG don’t seem to have cut any corners when they were putting these cans together.
General impressions on sound signature
The N90Q is a difficult headphone to characterise, as it effectively incorporates its own built in tweakable EQ and listener specific sound signature. It can range from relatively flat to aggressively U shaped with the twist of a dial. It also has its own DSP to manipulate the soundstage, again going from a ”flat” studio presentation to a more reverb-heavy “live” setting with a click of the relevant button.
The underlying signature is pretty well balanced, carrying a rich and extended bass, a nicely detailed midrange and treble that errs towards sharp but doesn’t quite edge into cutting. The N90Q cuts a good path between the three elements, keeping each in a relatively similar stage position when the EQ is set to flat, pushing the bass and treble forward and receding the midrange in stages as the EQ is activated.
Sub bass is extended but not overly heavy in trends of quantity, rounding out the sound in the lower registers without dominating, and adding a tone of roundness and warmth to the overall signature further up the range. There is slightly more quantity present as you move up to the midbass, the N90Q presenting a chunky and textured sound which moves a little higher than strictly neutral, but doesn’t approach basshead territory. There is plenty of punch and slam to the bass that is there, giving drums the sort of physicality and urgency that only a good dynamic driver can achieve.
Mids are highly detailed, and take the texture of the upper bass and add another layer of fine detail and resolution to the mix. The dynamic driver with its anti distortion design delivers in spades here, giving off a sound that packs in plenty of emotion and rawness, and populates the fringes of the landscape with plenty of subtle detail. The mids aren’t the most liquids you will ever come across, tending more to a dry and ever so slightly chalky texture in the ear, but achieving this without any noticeable grain.
Treble is sharp and delicate, having just enough control not to sound unpleasant on sibilant tracks but still carrying a definite edge and crunch. Harmonics of stringed instruments and other high range sounds glitter and sparkle, sounding delicate and almost gossamer-like as they decay.
Cranking the rotary EQ control on the left earcup switches the sound from a flat to U shaped signature in 4 stages, passing through a shallow and deep V in the intermediate points. For my personal taste, the shallow V is about as far as I like to go, injecting a little excitement and a more aggressive sound for some rock music without pushing the mids too far back in the mix. The U shape at the end pulls the stage too far in for me, and leaves the excellent midrange sitting behind the other elements of the sound. It may be useful for some taking”on the fly” but as with most tunable models I’ve tended to find my preferred setting and leave it there 90% of the time.
Overall, the N90Q present music in a relatively neutral but not boring manner, packing in enough detail to remind you that these are a high end headphone, but having enough dynamism and musicality to keep it fun and enjoyable.
The bass is deep, extended and ever so slightly north of neutral, with more of an emphasis on slam and texture than actual quantity. There is an air of solidity to most music, but the midbass occasionally leaves bassier tracks just a little lacking in body. Extension is good, handling the rich and velvety bass of Daft Punk with ease, feeling nimble and finely textured. The balance is fairly even between sub and mid in the flat configuration, and gains a slight sub bass emphasis when in full U shape.
Kicking into my test tracks, “Bad Rain” by Slash is handled pretty well, the kick drum intro to the track hitting with force. The growling bassline that follows at around the 20 second mark sounds textured, but isn’t the most authoritative depiction I’ve ever heard. There is plenty of definition to the edge of the bass guitar notes, but the main body isn’t huge, Cranking the rotary EQ gives more substance and evokes more of the feeling of menace this track is capable of, with the trade-off of less vocal and guitar presence higher up in the mix.
Sticking with rock, “Coming Home” by the prog rock supergroup Sons Of Apollo fares better, the rolling drum fill that kicks the track into gear plaguing across the back of the listeners skull with pace and power. Billy Sheehan’s adrenaline fuelled bass sounds suitably thick and packs in the texture, each note hitting with definition and precision that can be lost in the overall wall of sound on lower end gear. This is a good track for identifying how well a driver can handle busier tracks in the bass region, and the N90Q has no issues here. Each note of the bass and each drum impact is clearly defined, packing tightly into the lower end of the soundscape without smearing or loss of clarity.
Going looking for more sub bass, “Heaven” by Emile Sande and “Ship Goes Down” by Walking On Cars are served up. The AKG handles both well, providing a tickle in the inner ear as the sub rumble kicks in. It’s deep and extended but definitely on the lighter side in the flat configuration, so unless you have full EQ engaged this would not be remotely near basshead territory for the hardcore EDM fans out there. With EQ at full bore, the sub bass hits respectable levels of thrumming in between the ears, so if you are looking at these as headphones for genres that concentrate on the sub bass frequency range be prepared to engage the tuning circuitry or your own device EQ to get the best efforts out of this driver.
Overall, the bass is nimble, highly detailed and dripping in texture, but just lacks that final sense of body to elevate it to exceptional on some tracks. It certainly never feels anaemic, however, and provides an impactful and high calibre foundation to the music when called on. For listeners who prefer a more sedate and lean lower frequency response, this will probably be just perfect, but I can’t help craving just a little more out of the ultra-capable driver on occasion.
Compared to the bass, the N90Q has a more static midrange, with the EQ working on the frequency ranges either side but leaving the centre ground reasonably undisturbed. The stage positioning changes from neutral to slightly recessed depending on how far the EQ is along the U curve, but apart from that, the general constituents of the sound remain constant.
The mids on show here are finely textured and a little dry, with very high levels of detail and a slightly chalky edge to the sound. Vocals sound raw and emotional, each crack and whisper being accentuated against the black sonic background. It isn’t the most liquid or silky of sounds, but it does highlight the highly resolving nature of the 52mm driver AKG chose to use here.
Despite the emphasised edges, the N90Q stays remarkably clear of harshness, Chris Stapleton’s ode to liquor and sonic harshness “Whiskey And You” sounds powerful and delicate at the same time without shredding the inner ear like it can with some earphones I own. There is a control to the acoustic guitar chords that is exemplary, leaving the gently finger picked sound floating almost gossamer-like in the air around the vocals, accentuated by the fret and body noises of the guitar. The detailing here is genuinely immersive, pulling out bags of raw sonic information without overloading the ears or losing the musicality underneath.
Male and female vocals are treated similarly, with neither sounding overly lush but both conveying a good sense of emotional engagement and similarly high levels of detail and transparency. Switching to some more upbeat guitar fare, “Johnny” by Dan Patlansky sounds energetic and crunchy, the blues rock guitar work fizzing along in distorted harmony with the sandpaper-raw vocals, each edge feeling sharply defined and razor-sharp. The AKG fares excellently with guitar based music in general, having enough bite to deal with the raw riffing and slam of bands like Sons Of Apollo or Slash without losing the delicacy required to do justice to Jack Johnson.
Other stringed instruments are equally well rendered, “Theme” by the violin duo Duel dripping with emotion and timbre as the haunting melody plays across the track. There is a sense of blackness and space add-ons the midrange notes that is quite surprising for a closed back driver, the blend of thick and thin notes adding a sense of realism and a natural timbre to the sound. The AKG driver is capable of plenty of dynamism where necessary too, and while not quite on the same level as the uber-engaging Focal Elear, is credibly well suited to deal with the ebb and flow of classical orchestra and similar genres.
Overall, the mids here are very well delivered, with enough detail and texture to compensate for their slightly powdery tone on some tracks. It isn’t a midrange for people seeking a warmer and more romantic or lush presentation, but it is definitely an engaging and emotional listen, and very well suited to guitar based genres.
The treble presents a sharply defined and textured affair, with a decent dose of sparkle and no harshness. Notes glitter and crystallise against the background of the music, with plenty of air around them. The EQ dial can have a fairly large effect here, boosting the treble from a more full bodied and rounded affair into something thinner but more sharply emphasised (and just generally more sharp), accentuating the micro-detail and fine textures and harmonics if pushed into the full U configuration.
Listening to something like “We Found Love” or “I Need Your Love” by Calvin Harris is an enjoyable affair in the more V or U shaped modes, the swirling synth and hi hat sounds hanging crisply in the air around the vocal lines and getting the toes tapping effortlessly. EDM is definitely another genre the N90Q does well.
Moving back to rockier ground, “Starlight” by Slash is handled excellently, the harmonic-laden opening bars sounding crisp and screeching without becoming unpleasant. Myles Kennedy’s famously high vocals also get treated with respect, hitting the high (high!) notes with a mixture of definition and smoothness that makes the song soar. This is the N90Q at its most engaging, the raw sound of the electric guitar and the detailed high end bringing a sense of anima to the music. It can lack a little in physicality on occasion, but it is quite easy to get lost in the presentation.
Cymbals splash and decay slowly, hitting with a sizzle. Again, they sound more sparkling than solid, but add a nice natural energy to most tracks. That is a suitable analogy for the N90Q presentation in the top end, naturally energetic and crisp, but not overflowing with body or presence. It works well with the rest of the presentation in the V and flat configurations, bringing a real edge of detailing to the otherwise more balanced sound.
Soundstage, separation and layering
The N90Q is a closed back headphone, but due to the judicious use of DSP and other electronic processing, it manages to throw a decent sized soundstage around the listener. It wouldn’t be described as vast, but notes sound large and pushed a little way outside the head in both the vertical and horizontal directions. The the staging options don’t have a huge effect, but are noticeable, changing the relative position of the listener from front of stage/in the recording venue to sat back a few rows with a wider and more reverb-heavy “live” presentation.
The more live presentation also adds a little thunk to the bass, so works well in tandem with the onboard EQ to add a further tint to the sound. Even with the different stage effects, the soundstage feels more oval than truly spherical or “holographic” in terms of imaging, with the stage having slightly less depth than width. This is offset to a certain extent by the height, giving a sense of scale and three dimensionality that may otherwise have been lacking.
Separation is top notch, with plenty of space between instruments. The N90Q throws enough detail out to keep each strand of music keenly separated, with hard panned instruments hugging the sides of the soundscape and multiple guitar lines resolving themselves easily in the ear in more complex passages. This is helped by the relatively dry midrange and crispy treble, with the edge of each note being easy to identify. Layering is similarly good, as you would expect from something in this price bracket.
Unusually for something in this price bracket, the N90Q come with ANC built in. The implementation is actually pretty good – it doesn’t quite top the Bose QC35 or Sony MDR-1000X I’ve heard, but it certainly does a good job of eliminating a fair portion of the background noise on public transport or in a bustling office. There aren’t any additional modes or bells and whistles here, but it is quite effective at what it does.
Unfortunately, there is a small but noticeable background hiss effect with the ANC turned on. While this is effectively drowned out as soon as music starts, it is still a little unfortunate, given that the N90Q won’t work in passive mode, so you always have to have the ANC engaged. AKG seem to have done a pretty good job of avoiding the “airplane ear” type pressure build up that usually accompanies decent noise cancellation, but it would have been nice to be able to turn this feature off occasionally.
MrSpeakers Aeon Closed ($799, planar magnetic closed back headphone)
The Aeon Closed are a closed-back over ear headphone from Dan Clark’s MrSpeakers brand, retailing in a slightly lower price bracket than the N90Q. They are included here as they are also targeted at the “portable audiophile” market, with an emphasis on sound isolation and a very comfortable and low-profile fit.
Sonically, the N90Q give a slightly crisper edge to the sound compared to the Aeon Closed with the tuning pads fitted (my preferred configuration), but trade off a slightly more recessed midrange in all configurations as a result. The N90Q have slightly more mid bass in the flat configuration, with the sub bass being relatively equal to the slightly sub-tilted low end of the Aeons. The Aeon have a more “planar” texture to the lower frequencies when well driven, compared to the textured but slightly less solid feel to the N90Q. Speaking of power, the Aeon requires a lot more amping to reach its full potential than the AKG model. Volume can be achieved reasonably easily, but to pull the full substance out in the lower end, a warm and high-voltage swing amp like the ALO Continental v5 is recommended.
Moving up to the midrange, the notes are slightly thicker in texture on the MrSpeakers model when the pads are fitted, feeling a little more defined and closer to the AKG midrange when padding is removed. There is a slightly more organic feel to the Mr Speakers midrange in comparison to the chalkier tones of the N90Q, with neither pulling hugely away from the other in terms of overall technical prowess – if anything, the N90Q probably holds a slight edge here where it comes to technicality if you prefer listening to the Aeons with the warmer tuning pads in (which I do), but it’s definitely not a huge difference.
Treble is a little more sparkling on the N90Q, with a sharper edge to the sound and a thinner and crisper note presentation. The Aeons parry with a slightly fuller feel, with less overt crispness and a more linear progression up into the higher reaches. Both are very good technically.
In terms of staging, the Aeon Closed feels slightly more oval, carrying a little more width than the N90Q but not as much depth. As far as packaging goes, while the Aeon Closed is a beautifully presented headphone, the sheer luxury and breadth of accessories on the AKG package make it an easy win for the N90Q here. Finally, comfort is close, but edged by the Aeon with its lighter construction and more ergonomic fit.
Overall, these are both headphones at the top end of their respective price points, with a similar if not identical take on musical presentation. The N90Q is a great sounding headphone with a lot of additional bells and whistles, but for me, unless you are lacking a powerful enough source to properly drive them or really need noise cancellation or onboard EQ in your top-end headphones, the Aeon Closed is my preferred choice
Campfire Audio Cascade ($799, dynamic driver closed back headphones)
The Cascade is Campfire Audio’s recent entry into the over-ear headphone market, sporting a similar pricetag to the Aeon Closed in the previous comparison. They are a closed back headphone fimly aimed at the portable market, sporting a 42mm beryllium dynamic driver and an all-metal construction, designed to fold up for portable use.
In tone, the Cascade is a richer and darker sounding headphone, with an order of magnitude more bass presence than the N90Q, even with the full “U-shape” EQ engaged. Bass detailing is actually pretty similar, with the N90Q throwing a little more more obvious detail into the ear on first listen due to its almost neutral weight. In comparison, the Cascade provides similar texture and layering down low, but hits far, far harder, carrying a much bigger sense of body and weight through the notes. If you are not a fan of a north of neutral bass presence in your music, the N90Q would definitely be more to your liking, but if you do like a bit of low-end presence in your music without drowning the mids or muddying the sound, the Cascade pulls away quite significantly from the N90Q here.
Similarly in the midrange, the Notes hit with much more physical presence on the Cascade, adding a nicely accentuated lower edge. Vocals feel thinner and have a more “raw” presentation on the N90Q, lacking the weight of the Cascade. The N90Q has a chalkier and less dense presentation, which throws a little more air between instruments. The midrange feels slightly more forward on the Cascade, with the EQ progressively pushing back the staging of the mids in direct comparison on the N90Q. Detail levels are actually very similar when you listen critically, with the N90Q just shading it overall. Again, this comes down to how you like your mids presented – if you prefer a thicker and more musical tone, the Cascade will be your preference here, but if you lean more towards the analytical, the N90Q will probably shade it for your preferences here.
Treble is thinner and more sparkly on the N90Q, with the Cascade unsurprisingly coming through with a thicker and more weighty presentation, although again detailing is fairly similar. Both headphones have a tuning capability, with the Cascade achieving this through fittable felt filters (try saying that after a few frosty beverages), so the relative presence of the treble can be altered depending on your preference.
Packaging is another win for the N90Q, with the Cascade carry case being more practical than the AKG offering but the rest of the accessory loadouts going to the Quincy Jones model. Comfort again goes to the N90Q, with larger earpads and a more ergonomic overall fit, along with less feeling of weight on the head. Drivability is fairly similar, with both headphones being able to get more than loud enough from common sources like mobile phones, so don’t require any additional power to get to uncomfortable listening levels.
The build feels a fair bit sturdier on the Cascade, with the N90Q feeling more refined but a lot more fragile and less portable than the Campfire model. The Cascade gives you the impression that it could be used to hammer nails in around the home without any ill effects, while the N90Q is more of a traiditional TOTL headphone, so needs the usual care and attention to avoid turning it into a pile of components with harsh treatment.
The cable is a concern on the N90Q in comparison to the robust cloth sheethed effort that comes with the Cascade, with the thin 2.5mm connector and overall thinness of the AKG offering feeling a lot less hard wearing than the thicker cloth woven covering and overmoulded connectors of the Cascade.
In my recent review of the Cascade, I awarded it a perfect 5 across the board, so in terms of preferences there should be no surprise to discover that I think the Cascade is a better suited headphone for my preferences. It lacks the additional tech of the N90Q, but the sheer visceral power of the presentation allied to the high detail levels and dynamism just makes this a more compelling proposition for me. If your tastes err more towards the analytic and dry or you are looking for something a little less bass heavy then the N90Q is a great sounding headphone, but for portable use, I would stick with the Cascade as my preferred choice.
The N90Q are an unusual proposition in the TOTL headphone market. A closed back, tunable headphone that comes with an onboard DAC and some pretty effective noise cancelling. It’s almost as if AKG took an idea for a good top of the line closed back effort, and then gave it to their R&D team to throw as many other things at it as they could think of just to see what would stick. in practice, it succeeds on the most fronts, with just a few questionable choices. The bespoke ear-scanning and tuning isn’t as revolutionary as the literature suggests, but it does make a palpable difference to the sound being produced. Whether you will find it useful will be determined by how close you like your sound to be to the Harman target curve, and how much you want to engage the onboard EQ wheel, rather than finding one sound shape you are happy with and sticking with it.
The noise cancelling falls onto similar ground. Will you realistically take a £1200 headphone on public transport or a long-haul holiday to really get the most out of it? Do you live in a household where the background noise level is usually akin to the sound at pitchside before a major cup final? If so, then the well implemented AKG tech will be a revelation. If you are the sort of listener who sits in a quiet room with their desktop gear, the additional cone of silence will most likely pass by unnoticed.
The onboard DAC for me is a failed experiment. it may have been up to scratch when the headphones first went on sale, but compared to the output from the various sources I have been able to use, the AKG DAC just doesn’t quite cut it in terms of dynamism or resolution. If you have the funds to buy the N90Q but not any additional cash to spend on something like the Sony ZX300 or any of the Fiio/Ibasso mid-tier offerings, then this MAY be a useful feature, but for most people engaging with personal audio at this sort of level, your existing sources will already exceed the capability of this in-built decoder.
Once you get past the tech into the actual sound, the N90Q is a dynamic, engaging headphone with detail in spades and an overall enjoyable sound. It is comfortable and well-built, with an insane accessory pack and a decent sense of stage for a closed back design. Can it stand up to other notable headphones in this price range? It can certainly compete with the other models I have heard around this range, but it just lacks the killer sonic features to really pull clear of the crowd. To be clear, this is still a very, very good sounding headphone, and certainly the best sounding ANC headphone money can currently buy (by quite a margin). If you don’t need all the additional bells and whistles or the bomb-proof storage case, there may be more compelling propositions for the same price.
Overall, the N90Q sounds like a TOTL offering, and will appeal to people seeking a highly detailed but flexible sound, so if that sounds like you and you like having as much tech on your head as you can possibly carry is your thing then you won’t go far wrong here.