K812PRO Superior Open-Back Over-Ear Reference Headphones

My first serious headphone was an AKG and I have always had a bit of nostalgia for the brand. However, through endless iterations, and since the early days of K1000, AKG produced more of the same. I was therefore intrigued when a new flagship was announced, however due to mixed reviews I held off until was able to get this for a competitive price. Straight out of the box, and based on looks and build quality alone, this is my new favourite. Sturdy, classy, understated but at the same time quite comfortable (I say "quite" because it is not exactly lightweight). I read a lot of talk about the cable. While I am a believer in cables and spent thousands on expensive experiments, I believe that a cable can not change the fundamental sound on a system, but rather add subtle finishing touches to a well tuned sound. In other words, yes, it is a rather thin and cheap looking cable but it does the job, it is virtually invisible, no microphonics, no thick heavy ropes hanging from my neck, I have no problem with it. As far as sound is concerned I am primarily a speaker user and my headphones are rather a hobby. In the past I tried many and owned plenty of the flagships - Denon D7000, Beyer T1, Senn HD800, Grado GS1000, several Ultrasone Editions but also played with much cheaper products - including the usual suspects HD6XX, K70X etc. I am not ashamed to admit that I even have a couple of Bose products in my collection for their noise cancellation prowess, a JH13 Pro and other various bits and bobs. Now this AKG - how to put it. I understand the love and I understand the hate. I understand the waxing and the bashing. And the funny thing is - they are all right. If I would have to give a personal verdict I would say: I love it. So you know what to expect from the beginning. After having all of the above headphones I absolutely unconditionally love this one. It is by no means perfect, pleasurable, "audiophile", it doesn't wow me but there is so much right in this headphone that I don't even know where to begin. A lot of people mentioned the balance and yes, it is expertly balanced. There is low range, an exquisite midrange, there is plenty of treble. Now if you have ever heard an Audeze or like the heft of a closed woody headphone, K812 will not cut the mustard for you. But if you think HD800 has a good low end and you are happy with it's overall reproduction of bass, you have to hear this one. Although it doesn't have a lot of low end, it doesn't "hit you hard", it doesn't shake your temples, it is the kind of bass you get, in quantity as well as quality, from a near field monitor in an average room. Also a lot has been said about the distortion below 40Hz. I don't have a problem with this, I don't hear it, I don't think that much can be heard below 40Hz as at that frequency you rather feel than hear. But here's my two cents. In my early days with Dirac on my multichannel setup, I was trying to achieve this perfect curve and the sound was lean and was missing body and true colours. At some point I discovered that by setting up a high pass filter at about 60Hz and allowing some distortion below, I was getting a much more realistic sound. So if there is distortion below 40Hz, I don't have a problem with it, I can't hear it and, to my ears, the low end is just about the best approximation I have heard in a headphone of a near field monitor. The midrange of this headphone is epic. I can go on and on and on about how beautifully voices come through but much has been said about it so I will not repeat it. Plenty of reviews, nobody is denying it. If you like female vocals, you have to give this headphone a try. Krall, Bremnes - bliss. Which is no surprise since AKG have always been masters of the midrange - think for instance K501. Now the treble which plenty of critics describe as harsh, unrefined, raw, bright. My position is that it is all of that. And it isn't. If you come from the "audiophile", mellow, ethereal HD800 or lush T1, it is. And there is certainly a drop in micro detail, resolution, air compared to a HD800. But I always found that HD800 paints a romanticised landscape because in the concert hall or in front of my monitors I hear none of that. Yes, HD800 can dig deeper into the recording. But that stuff I can not hear on K812 (although an exceptional achiever in its own right) was never meant to be heard. You will not hear it in the concert hall unless you are on stage, in the middle of the live performance, you will not hear it on your speakers unless you listen with your ear pressed against the speaker, on a highly resolving system. The word that comes to mind again is: realism. AKG K812 equals near field monitoring. Are the Yamaha's and the Genelec's and the Mackie's sweet and delicate and ethereal? Do they paint a pretty, sugar coated picture? Are they soft, silky, velvety? Is that the sound you are after? Then this K812 is not for you. But if you want the sound of your Yamaha's and Genelec's and Mackie's in a headphone, this is the closest I have heard so far to the real thing. At the right volume (which is not too low but neither too high), AKG K812 sounds pretty much indistinguishable from my speaker setup. I went over and over again over the same recordings, played on many speakers over the years and plenty of headphones, heard in concerts. K812 is not a concert hall experience. For that you have HD800 and HD650. It is not a floor standing speaker experience on some massive class A mono blocks either. K812 is the bookshelf, near field monitor experience. And if you value this rather intimate audition versus the massive concert hall, the big floor stander in the big open space, K812 is stunning. It takes you there, it has no musical preferences, it works equally well with classical, acoustic, jazz, rock, electronic. And it does all this plugged straight into an iPod Classic because it is also the first AKG flagship that does not need massive power to shine, although it will benefit from a beefier and more resolving system. It is a bit bright but near field monitoring is bright. It is a bit unrefined but electrical guitars are not refined and try to play Metallica on HD800! However, having said this, listen to Bremnes' voice on HD812 and tell me if you have ever heard a headphone, any headphone near this price range, that can do a better job at bringing her to life. It might work for you or it might not. If you think Benchmark sounds lean and harsh, if you can't stand a Mackie or a Yamaha near field monitor, if you are a Berilium tweeter fan, it's probably best to skip this headphone for the high end Focals or Stax 009. But if you value near field monitoring, if you want to hear it true rather than pleasurable, K812 might be a revelation. I can only hope, with all the rumours going around, that this is not AKG's last flagship.

Ok, some will say I am just a AKG fanboy but I also own Grado RS2i's & the 'legendary' Sennheiser HD600's but the K812's are a really worthwhile upgrade over my AKG K702 65th Anniversary headphones. So they should be at £938. I have read every online & magazine review around on the K812's and ended up somewhat confused, the first lesson is to trust your favourite headphone manufacturer to produce a fabulous flagship headphone and not to get to get bogged down with the minutiae within some of the reviews. The headphones arrive in a simple but attractive box and AKG provide a lovely wooden headphone stand which is more useful to me than an aluminium box (I bought two sturdy but light headphone boxes from Amazon for £15 each and they accommodate any of my headphones for when I travel abroad). The materials used in the construction of the K812's are of great quality, they look prestigious and are very comfortable. I particularly like the larger than average earpieces which provide plenty of room for your ears and seal the earpieces to your head really well. I don't need a 3m cable so I will be ordering a 3ft cable from Double Helix Cables who make very high quality headphone cables. Lot's of headphone porn on their website... I resisted listening until the K812's had had 24hrs listening to songs on their own via my laptop, yes, I do believe that things like headphones & loudspeakers need running in but let's not get into that debate please! I only use headphones with my two digital audio players, Cowan Plenue 1 & Colorfly C4 Pro, so I welcomed the easier to drive K812's compared to my K702/65's although I chose both my DAP's because they have healthy power outputs, I'm using noticebly less than I was. The K702/65's produced enough bass for me but the K812's produce a much better quality of bass, better defined, more tuneful, doesn't become befuddled when put under pressure, goes nicely deeper so a real improvement in the bass. I started listening to Emeli Sande's wonderful 'Live at the Albert Hall' CD/DVD and the K812's reproduced her voice beautifully providing more clarity and detail to her voice than the K702/65's, more emotion was conveyed. I have written about the K702/65's that I would have liked a bit more treble bite & intensity & I'm delighted that the K812's provide this, I am listening to Arena's new album 'The Unquiet Sky' as I type this review and I am hearing more of Mick Pointer's cymbals and a more vivid version of John Mitchell's fantastic solo guitar work. Some of the reviews have talked about a treble bite as bad as a pit bull terrier's but I haven't found this but equipment partnering is very important and the Cowan Plenue 1 is described as an 'analogue' type of sound so isn't going to provoke an excessive treble bite from the K812's. I find the Colorfly C4 Pro less good with the K812's but it is an earlier generation of DAP & £200 less expensive than the Plenue 1. The other thing is that I'm in the 50-70 age group and my ears are less sensitive than The Child's (in her twenties) so I know she would have a different point of view but as most 18-30's either couldn't afford the K812's or are simply not nearly interested in music to spend substantial sums on music equipment, perhaps AKG tuned the K812's for the average buyer? Last year I visited Hi Fi Lounge, the top notch hi fi dealership run by Paul & Wendy Clark who have one of the very few dedicated headphone rooms, in fact it's not a dedicated headphone room nowadays, it is a dedicated headphone building adjacent to their hi fi building. I visited before the dedicated building was opened but I was able to listen to a variety of headphones in the £800-£1,700 range (good thing The Wife doesn't read my Amazon reviews!) and whilst one had nicer bass than my K702/65's, I didn't like its treble, another was more open in the midrange but lacked bass, another had too much bass but a lovely midrange & treble! On it went, sadly Paul wasn't an AKG dealer. So it ain't quite as easy as it might seem, regardless of budget, to find a 'perfect' pair of headphones anymore than my very substantial Hi Fi system is perfect either. The £££££ speakers are fabulously clear (a bit too so with some recordings), have beautifully defined and very quick bass (but could do with a bit more with most recordings). My last speakers (PMC) had lots of transmission line produced bass but on most recordings I could hear the bass lagging behind the rest of the music notwithstanding the high quality amplifiers powering each speaker separately. So as Arena's great new album demonstrates, the K812's give me what I personally wish from a flagship pair of headphones so I would encourage you to buy the AKG K812's if you are a music lover as I am. They give what my K702/65's were unable to produce and more besides, can't ask for more than that. September 2015 Update: My K812's are now well run in and sounding worth every penny (I see the Amazon price has gone up by £130!), I have listened to many of the albums on my Cowan Plenue 1 and I really love the sound. I have upgraded my USB headphone amplifier to an Audioquest Dragonfly v 1.2 with an Audioquest Jitterbug and this has made a useful difference to all laptop listening. The quality of the K812's has resulted in my listening to music far more than I did using my K702/65's which is a testimonial in itself. The 10ft cable supplied is annoyance and I am delighted my Double Helix Cables 3ft cable is now on its way from the States (DHC Elite 4 wire Fusion hybrid silver/copper OCC Litz). A cable of comparable quality to the K812's, can't arrive soon enough, why can't AKG also provide a 3ft cable?

If I buy a new piece of hi-fi equipment, I can guarantee that a colleague or friend, upon finding out, will ask how much it was, and if I tell them, they will then ask why I spent so much on it. I particularly treasure the comments of one female colleague who will berate me for spending e.g. £1000 on a new amplifier, whilst I know that this sum is dwarfed by what she has spent on designer shoes, most of which she finds agony to walk in. The simple fact is that everyone has (and should have) their indulgences, and given the choice between bunions and thousands of hours of listening pleasure, I know which I'd choose. I preface my review with these comments because these are, by any reckoning, an expensive pair of headphones. Why on earth should anyone in their right mind pay this much? Well, there is no short answer to this. Headphone and speaker technology has come on leaps and bounds over the past twenty years, and you can buy a pair of headphones for £50 or so now that would trounce the top-ranked 'phones of a couple of decades ago. So if you want a pair of headphones that will give you reasonably distortion-free playback, with decent stereo separation and a nice wide frequency range, then you need only spend around £50 to get what you want. And for most people that is fine. Really and truly, if you are a casual listener to music, and have no intention of listening for any great period of time over 'phones, then don't for goodness's sake buy the K812s - they will do a great job, but you are over-paying. These phones are for two types of consumer. First, professional musicians and music producers who need an absolute fidelity of sound when mixing songs in a recording studio. Second, hi-fi nuts who are obsessed with getting the best possible available sound reproduction. As the other positive reviews have already made clear, the quality of the K812s is stellar. I've never heard better than these, and I've heard all the top-end makes (Sennheiser et al) before you get to the cuckoo-priced limited editions at £5000+. Sticking to the 'phones you can buy from a typical hi-fi shop, there are equally good high-end 'phones (all the same price as the AKGs or even more expensive), and some folks might prefer these. Even at this price there is room for some differences in sound presentation. For example, if you want really deep bass dominating all, then the K812s will probably fall short of expectation (though there is bass there a-plenty). They also aren't the 'warmest' sounding headphones on the market - again, this is a price you pay with any system - you can have analytical or you can have warm, you can't have both. BUT: I seriously doubt that allowing for preferences such as these, you will hear anything better. My personal take on the sound quality is that it's rock solid in presentation. In other words, when an instrument comes in, it stays in that spatial position, and doesn't appear to shift or go hazy as it changes volume. This might sound a relatively arcane point to make, but it is the thing that crucially makes the K812s stand out. The frequency range is excellent, but be warned, you need to play these 'phones for a good many hours before they will sound their best. When you first listen to them, if you are already used to top end 'phones, you might well think they sound tinny. Just give them chance to wear in - like nearly all hi-fi equipment, it will take a good many hours for these 'phones to reach their best. I am still wearing mine in, and the sound is gradually sounding less frenetic and more assured, but I know from listening to a friend's pair of K812s that they will get better still. So, should you buy these? If you are a studio engineer or a hi-fi nut, then yes. But if your first thought on seeing the price was 'I could get something better than headphones for that money' rather than e.g. 'wow! I wonder what makes these special?' then you probably should find something else to spend your hard-earned cash on.

I recently bought both the AKG K712 and the AKG K812 so have put a review comparing the experience under both. 30 years ago, I bought a set of AKG’s – the K 280. These are called parabolic and have two speaker coils in each ear. Always liked these but I decided to treat myself as technology has moved on a bit since then. I am in my 60’s so ears not so good. Kit is an Arcam rHead, iRdac II, A39, CD37, Heybrook TT2 deck. Various music both CD and vinyl. I got the K712’s first. The sound was definitely an improvement on the K280, but not the upgrade I expected. Also, not too keen on the pads – like a foam material that could damage easily. They fit well and are comfortable so I could wear these all day. The sound was engaging - good soundstage and separation of instruments, and bass was much better than I thought it would be. Much much better than the usual headphones with funky names that people wear on the train! I would say these are a good HiFi set of cans for ‘serious’ listening. However I wasn’t totally blown away with these so looking higher up the tree I decided to get a pair of K812’s that Amazon had as open boxed for £520. If the reviews were right then this would be the upgrade I wanted, and I have 30 days to send the K712’s back. So, the K812’s turned up and the box looked tatty, the headphone pads looked a bit ‘second hand’ so I took pictures just in case I went them back and they thought I had misused them! Now came a couple of days using both sets with the rHead; which has two headphone sockets so comparing between the two was easier. First thing I noticed was the K812’s sound louder 36 Ohms vs 62 Ohms for the K712 means they will. That makes comparisons difficult so I figured where on the rHead volume control gave the same level then went at it again. How difficult it is to compare the two. Old ears and the fact that the hearing plays tricks unless you are in exactly the same headspace and playing exactly the same music! I have had to spend hours drinking just enough red while listening to loads of newish music and my old sounds (Floyd, stones etc). I can’t give a scientific analysis but the K812’s wins out in every piece of music – not by a huge amount but the difference, if you can afford it, is worth it. The subtleties that are in music seemed effortless (or should I say more noticeable / clearer) with the K812’s. The rHead is a fantastic class ‘A’ headphone amp that lets me hook the CD or the turntable straight up – with the AKG’s it is perfect. Be aware though a couple of times I thought the coils might be off but it was simply flaws in the recordings. Once I knew what to listen out for the flaws showed up in other headphones on cheaper amps as well, just not so clearly. I am delighted I can still appreciate good headphones at my age, I know the frequency range my ears are good for has dropped, but the frequencies I can hear are well served by both of these headphones. The K812’s does a better job (for a bigger price) so I am going to send the K712’s back but I have a sneaky feeling I am going to have to audition a set of B&W P9’s before I am satisfied I have the ones for me.

Straight into the review, I used arcam Rhead (£300-400) and creative Xfi Titanium hd (~£100) The box is very nice with a fabric finish. The headphones were packaged very well and were on the stand (that comes with it) inside the box. Out of the box it was obvious they had been built with care and the quality was superb. Very comfortable to wear and not a single part of your ear touches anything (once they are adjusted to fit your head). The sound on first listern was incredibly clinical and very sharp. It was clean and the imaging was fantastic, but i wouldnt say it was enjoyable sound, not bad , just not relaxing. This however, mellowed out after a few days and now the sound is wide and smooth and an absolute delight to listern to. The accuracy of these headphones is jaw dropping , sometimes this is a benefit but others not so much. Some songs do have an over exaggerated "ssssss" sound on some lyrics but this only happens on a handful of songs and this shouldnt put you off these headphones because in every other respect they are WOW. These headphones have deep bass (not to be confused with skull crushing bass) and beautiful mids and highs that sparkle! I also use these with movies and games and they perform just as good with these aswell. I have had quite a few sets of headphones ; shure srh1540 (~£400), akg k712 (~£220), HD 700 (~£450) and where as i love all of the above for different reasons my favourites by far are these AKG K812! Last point to make i bought the AKG K812 on a lightening deal for £560 on black friday, but having listerned to them i would have been happy paying the £730 amazon are charging now. Bearing in mind double the price does not always mean double the quality but from the k712 to these i would say it does.

Listening exclusively to well recorded classical orchestral music, these are genuinely top flight headphones. Reproduction of strings, brass and especially timpani is thrillingly realistic. Placing of particular instrument groups is crystal clear. These are superbly analytical headphones, but this adds to rather than detracts from the listening experience. On brighter and early digital recordings, a less analytical presentation is sometimes preferable. In those cases, I preferred the Beyer T1. I found the K812 superior in every respect, on every recording, to the Sennheiser 800. The headphones are well built (in Slovakia), with no rattles or squeaks after 2 years. Sadly AKG are no more, so if you want these headphones buy them now. Last chance! I listened via Chord Mojo and 2qute dacs, with a Lehmann Linear amplifier. Also straight out of an ipod using lossless recordings, which was perfectly viable. I compared them to similar flagshps (HD800 and TI), also cheaper sets (HD600, 880, K701, Sony MDR Z7).

As a musician, I found these impossible to use, as they give great top levels but not lower, which for mixing is a nightmare. Also they leaked so much sound and let in the sounds around me, that I had no choice but to return them. I would only recommend to a musician with a soundproofed studio and excellent mixing skills. These don't enhance your experience if you have a "normal" life. With a very heavy heart, I had to return these beauties as they can't work with my lifestyle. They came in a beautiful box with a wooden base to place the headphones on when not in use, thus keeping them in shape. Pity they were so unusable for my life as a musician. I really feel these are overpriced, as I've made an album on far less quality than these and had great success.

Headphones arrived from Barcelona within three days. All original sealed packaging without so much as a scratch. These are beautifully made headphones and extremely comfortable to wear. They have been a revelation to me, I shall be selling my Stax and Sennheisers. Seemed a little too bright at first but after a week's heavy listening they have calmed down beautifully. Nothing is missed, the dynamic range is huge as is the sound stage.I am hearing things in quiet passages of music that even my Stax ear-speakers miss! My principal listening is classical, orchestral, choral and organ.

Una delle migliori cuffie che ho provato, suono dinamico e ben dettagliato in risposta in frequenza. Con il DAC Chord MOJO 2 avrai un sistema ad alta fedeltà. Un po' costose ma nella media per il livello.

Estoy disfrutando la música con estos audífonos como nunca antes, y esto quiere decir mucho. Con ellos te olvidas del sonido y te metes en la interpretación. He tenido los HD800 y aún tengo los HD650 y los DT880. También tengo actualmente los Audezze LCD-2 non fazor. Pienso que los K812 superan a todos los anteriores. Sin embargo, deben usarse con un ecualizador para un resultado realmente superior. No es un caso exclusivo de estos audífonos, pues ningún audífono es realmente plano. Yo uso el True-Fi de Sonarworks, con resultados espectaculares. Tengo entendido que los HD800 originales también suenan excepcionales con True-Fi, resolviendo con ello todas sus deficiencias. Estos audífonos tienen un problema: con ellos salen todas las deficiencias del resto de tu equipo... ACTUALIZACIÓN AL 18-V-18 La equalización ha dejado de ser necesaria. Al parecer, estos audífonos son sensibles a las horas de uso. Conectado al Audioquest DragonFly Rojo es como he logrado mejores resultado, incluso mejor que conectado al Mojo de Chord. Aconsejo iTunes y BitPerfect. Increíble sonido, cada vez más satisfactorio. Maravilloso!!! No he tenido buenos resultados con Amarra.

Ce casque semi-ouvert a une bien plus forte réponse impulsionnelle que la plupart des casques de cette gamme de prix (j'ai des Sennheiser, des MrsSpeakers bien plus chers, des Oppo, etc.), Il rend la musique plus vivante, donc à recommander pour les musiques dynamiques (hardrock, metal, ou musique classique du genre des concerts de Vivaldi).( A ne pas écouter avant de se coucher tellement il est plein de vie) Pour la largeur de scène, différentiation spatiale des instruments, le niveau de détail et le confort il est très bien mais reste en dessous du Sennheiser HD 800 qui est une référence imbattable et que je préfère pour les autres types de musique ou les films. A note 2 petits pics dans les aigus et une faiblesse dans le bas des basses que j'ai corrigés avec l'égaliseur de foobar2000 sur la base des courbes (amplitude en fonction de la fréquence) établies par Tyll Hertsen sur son site innerfidelity. Le principal défaut du casque est que le fil n'est pas détachable, c'est vraiment dommage et c'est pourquoi j'avais attendu pour l'acheter que le prix baisse de 1500 à environ 1100 euros. Il est très facile à alimenter, se combine parfaitement avec le DAC-ampli Pioneer U-05, et peut bien s'utiliser avec un baladeur Astell et Kern en mode stationnaire (par ex. au lit; je ne me promènerais pas avec pour ne pas prendre le risque de casser ce fil qu'on ne peut pas remplacer.)

The AKG K812 was introduced in 2014 as a professional headphone and marketed as such. AKG fumbled the ball here and may have brought about their own demise, as these headphones could have been marketed as a TOTL audiophile headphone as well, seriously competitive with Sennheiser's HD800 (now the HD800S) and Beyerdynamic's T1 (now at Generation 3). Unfortunately, this never happened and samples to listen to were thin on the ground. I took a chance with the K812 headphones and they remain my favourites, even more so with a little modernisation using Oratory1990 EQ to bring up the deep bass and take the edge off the treble. IMHO, they are about on a par with the Focal Utopia OG sound wise, and are better constructed than the Focals. Anyone thinking about a TOTL headphone needs to hear these. Buy one soon - they have never been cheaper than at Amazon currently (they were AUS$1546 when I bought mine). Hopefully, AKG will one day produce another masterpiece like this. Sadly their audio design team appears to have been retrenched at about the time of the move to Slovakia of their main HQ. The design team is still doing excellent work at Austrian Audio and Mysphere.

Bien, la verdad es que Akg ha logrado superarse a si misma, de hecho, es el cuarto auricular que tengo de la marca tras los 272hd, 701, 702 y desde luego ninguno suena como suena esta bestia. Diseño: mas o menos lo típico de siempre, evidentemente han evolucionado pero siguen manteniendo el espíritu Akg. Construcción: están muy bien hechos aunque dan la sensación de que se van a romper en cualquier momento, pero no, aguantan bien y se ajustan a la cabeza muy bien, de hecho si te pones otro de la marca notas la diferencia en la presión que ejercen, pero en ningún momento molesta y puedes estar horas sin fatigarte. Los materiales usados están bien con partes metálicas y el resto de plástico que en general son de buena calidad. En cuanto a las almohadillas son muy suaves de material de efecto memoria que se ajustan perfectamente al contorno de la oreja y resultan muy cómodas, es posible que al principio notes las costuras pues están cosidas hacia dentro pero en poco tiempo se doman y ya no las notas. Algo que podría mejorarse es el cable, no por calidad,es el típico de la marca con conector Lemo, sino por la presentación pues no le vendría mal que estuviera recubierto de algún tipo de malla simplemente para que fuera algo mas elegante. También destacar que el conector xlr aun siendo de alta gama es mas pequeño de lo habitual y puede ser un inconveniente si quieres cambiar el cable, aunque se pueden encontrar. Un punto a favor es que vienen con un soporte para dejarlos colgados cuando no los usas de madera contrachapada bastante elegante, cosa que se agradece. Sonido: aquí es donde realmente se diferencian de cualquier otro ya sea de la marca en si o de otra marca pues el sonido que dan es realmente increíble, de hecho ningún otro que tengo ahora mismo me suenan bien, y me explico, por ejemplo, las voces tienen un timbre y una claridad especial, mas natural, el sonido de las guitarras no lo había oído de esta manera, es mas he llegado a oír el sonido de los dedos al deslizarse por las cuerdas de una guitarra española, increíble pero cierto, y ese es el tipo de detalle que caracteriza a esta maravilla de auricular. Como buen Akg que es, el sonido tiende hacia los agudos pero con un nivel de detalle que te deja desencajado, no por que sean chirriantes ni difíciles de soportar sino por la calidad que aportan, siempre se pueden ajustar al gusto de cada uno tirando de ecualización ya que cada oreja es un mundo y lo que a mi me gusta, a ti igual no. Las frecuencias medias son excepcionales, también con un detalle impresionante, y en cuanto a los graves pues bueno es como si estuvieran en un segundo plano pero que se aprecian, es decir están pero sin tapar a las demás frecuencias y como he dicho antes las puedes ecualizar para que suenen mas, cosa que es típica de la marca que parece que dan poco pero están. En cuanto a escena sonora, yo diría que se encuentra prácticamente al mismo nivel que los 702, pero con mas garra, mas caña y mas potencia, con una acústica muy difícil de batir que llenan por completo toda la oreja. Amplificación: bueno aun siendo de 36 ohm agradecen ser amplificados, yo los he probado con varios y la verdad que mejoran mucho dependiendo de cual se use. Personalmente prefiero los de válvulas que los llenan mas que los de transistores. De transistores o normales, probado con, Burson Soloist SL y Schiit Magni, en este caso el sonido es bastante parecido, no así el precio y solo me atrevería a decir que el Burson le da algo mas de calidad a los agudos, pero por lo demás no merece la pena gastarse tanto pues no hay tanta diferencia de sonido, pero con ambos el sonido es muy bueno. En cuanto a válvulas he utilizado el Little Dot MKIII con valvulas Mullard CV4010 y aquí si que la diferencia es notoria con respecto a los de transistores, llenando los 812 , dándole ese empujón que hacen que suenen de otra manera, algo mas cálido, con mas cuerpo y mas amplitud, eso si en ambos casos utilizo como fuente un dac Musical Fidelity V90. Con respecto a estilos de música van muy bien con trance, pop,e incluso con heavy aunque adolezcan algo de graves el sonido de las guitarras es increíble . En fin, estamos ante un producto que vale lo que cuesta, pero que si no te gusta el sonido Akg, mejor prueba con otra marca pues seguramente no te acaben de gustar por el perfil sonoro que tienen, pero si te gustan por ejemplo los 702, estos te van a encantar. Conclusión, gran sonido con un detalle impresionante, indicado para los amantes del sonido Akg.