Old School Trio: AKG K701, Beyerdynamics DT880, Sennheiser HD650

Soundstage Evaluation

There are several factors that I consider when evaluating soundstage:

  • Width is how wide left and right the soundstage is.
  • Depth is how far the soundstage extends in front of you.
  • Center area is how well can a headphone fill in the area in front of your face, and not just the area on the sides.
  • Separation is how clearly separated are one instrument from the next.
  • Imaging is how true-to-life is the reproduction of the arrangements of the band/orchestra.

Having established those parameters, the K701 scores very highly in the width and instrument separation, where you can see every instruments being individually isolated and laid out on the wide soundstage. My complaints with the K701’s soundstage is mostly with the imaging performance, as the lay out of the band and instruments doesn’t follow a logical live concert pattern. The K701’s soundstage is mostly felt on the left and right side of the head, and with very little information on the front. This may give a false impression of being immersed in the sound, as you would feel the instruments coming distinctly from left and right. But on the real world, bands and orchestras perform in front of you, not on your sides around you. And so the front/center soundstage is very important to a faithful reproduction. This is where the K701 fails heavily, as there is very little information on the front/center area of the soundstage.

Another factor that deeply disturbs the K701’s soundstage presentation is the lack of air between the instruments. The K701 separates the instruments very well with distinct distances between them. Yet, the background is almost too clean. Live recordings almost always have a small amount of air sound — that is, the sound of the air moving around the microphone. And it happens that this air is very critical for achieving a realistic ambiance. On the K701, the air sound is non existant. And while that may help give a clearer separation between the instruments, ultimately it makes the instruments disconnected without a proper “air” between them. It’s like taking a photograph of 5 people, cropping them in Photoshop, and laying them out in a perfectly clean white background. You get a very clean look at the subjects, but the photograph wouldn’t look very realistic.

The DT880’s soundstage is a little narrower than the K701, but it also improves on the aspects that I find to be more important for a realistic imaging. First, the “air” sound is not eliminated in the DT880. If your recording has that sound, it’ll come out in the DT880. Next, the center area of the soundstage is not blank as in the K701’s. The DT880 ultimately gives a more realistic view of the soundstage, with proper information coming from the front and expanding naturally to the sides.

Perhaps the biggest surprise of all is how I find the soundstage of the HD650 to be the best among the three, though under one condition: good source and amplification. On lesser systems, the K701 and the DT880 will give a more consistent, big and wide soundstage. Though they improve with better amplifiers and better sources, the improvements is limited to a certain extent. The K701 will continue to have some void in the center soundstage, while the DT880 only improves very slightly on the width and depth of the soundstage. The HD650, on lesser systems, feels fairly closed and claustrophobic. However, as you provide better amplifiers and sources, the HD650 improves tremendously. And I feel that the HD650 is the only one among the three that’s worthy of big amplifiers like the Zana Deux or the Beta22. The soundstage will expand tremendously, in the width, but also in the depth. The HD650 certainly has the most impressive depth of the three. Not only is the depth very good, but there is a very good projection of instruments that lay in the front and the back area of the stage. Like the DT880, the HD650 maintains the sound of the air between the instruments, and even more. I still feel the DT880 to lack the necessary soundstage depth to create a three dimensional image, but the HD650 is very good at this aspect. The HD650 ultimately gives the best ambiance among the three, and playing a well recorded live music like Buena Vista Social Club, the HD650 sounds far more engaging and three dimensional than the other two.

Old School Trio: AKG K701, Beyerdynamics DT880, Sennheiser HD650 2.88/5 (57.60%) 25 votes

  • Milko Georgiev

    Even HD600 has too much bass. R&B and other bassy music sounds like you are in a barrel. Mids are weak. AKG K701 and K712 give enough bass and still sound balanced, natural, nice, with no offence. Boom-tataa-boom is not the root of the misic 😉

    • http://dalethorn.com dalethorn

      I thought the K712 was very nicely balanced. I’m surprised to hear that the HD600 has a warmer or bassier sound, but it’s been more than 10 years since I had the HD600, so can’t compare them. But the K712 is a much newer design, yes? I think the Sennheisers are just too old, and look what they’re making now!! Momentum, Momentum junior, and (gasp) the Urbanite!

      • http://realmegapixel.com Milko Georgiev

        Yes K712 is an noticeable upgrade of K701.
        I’ll try Momentum, thanx for the advice.
        In my opinion Sennheiser (as many others) gives people (what they want) more disco/club feeling.


  • Ritwik

    Hello Mike,
    First thank you for this great article. I am relatively a noob and just been 2-3 years in this business. Got hooked by cheap Sennheisers which are easily available here or any part of the world. From Senn 180 to PX90 to CAL! and then Logitech UE6000 to M50 and now again I was in lead for a deal this time a used K701. Honestly, I never intended to buy an AKG more so because it’s total absence from Indian market. As with almost every full sized headphone enthusiast I was too looking forward to upgrading to 600(again unavailable in India)/650. But, the added cost of an expensive amp is what is holding me down for a while. Out of the blue a K701 popped up for sale and got me interested for what great many things I have read in the forums. Still, hungry and need for a more informed decision landed me here. And, it’s been an eye opener. I actually can understand exactly what you mean by this article. Why people tend to exaggerate one or a few traits making them characterised into extremities. Now, I am clear headed. I am going with the K701 which can easily be driven unamped or might make a good pairing with my Fiio E11. I found the Fiio not to my liking on M50 or any other cans as they all have sufficient bass and Fiio sounds very closed so had put up for sale. I will keep the M50 for v-signature and K701 for vocal/instrument till I can afford a decent 650 based setup. Meanwhile, might soon upgrade to a better Fiio DAC+AMP like E17k if this pairing worked.

  • Peter Harlovic

    I really fail to understand why audio ‘reviewers’ always seem to obsess over products that produce a so called ‘warm’ sound and try to describe such products as being better for music.

    ‘Warm’ is a term people use to describe a product that overemphasiss the base and/or midbass (300hz down) which tends to drown out all detail and leave you with a completely unnatural sound.

    It also leaves me wondering when reviewers start to describe some speakers/headphones as being ‘rock headphones’ or ‘jazz headphones’ and the like.

    A speaker is a transducer – it converts electric impulses in to sound energy. A speaker does not know if it’s playing Rap, or Jazz, or Rock. It colours every piece of music / source in the exact same way.

    Ultimately the most linear a speaker / headphone measures, the more accurately it reproduces ALL source material.

    When it comes to sonic accuracy, the HD650 is very clearly the worst performing product of this trio. It’s the strongest exhageration from 200hz down, and it’s got easilly the weakest output above 3khz. It’s relatively accurate 300hz to 3khz, but even over that range ti’s no more accurate than the K701 or the DT880.

    The Beyer actually has (by a significant margin) the most accurate bottom end of these three products, with strong bass extension that’s around -3dB at 25hz. The HD650 by comparsion is -3dB at around 40hz, and the K701 is -3dB at around 50hz. Anybody who describes the DT880 as being ‘thin’ down low has no idea what they’re talking about, because no audio system that plays down to 25hz (i.e. below the typical human’s audible hearing level) at -3dB can be described as thin or lacking extension.

    If the DT880 does in fact sound ‘thin’ then that would be because of the 3-4dB dip in the midrange (between 1k-3k) and may well be made more prominant by the ~4dB peak in the highs up around 7k-9k.
    Overall, neither of these heaphones measures truly accurately, but the K701 is the closest to it. It’s almost dead flat from 600hz to 4khz (giving it by far the most accurate midrange of the three) the bottom end is not too overemphasised (as most headphones are) and the highs are much more ‘full’ than the HD650 without quite so much peakiness as the DT880.

    At this stage I’m still favourable towards the lower end K601, which probalby has the most neutral frequency response of any headphone i’ve heard – though it’s distortion levels aren’t quite as clean as the K701 and the DT880.

    I’m eager to hear the K702 however – it looks to be somewhat of a merger between the K701 and the K601, with the low distortion levels of the K701 and the more extended bottom end of the K601. Should be a fantastic model, and trying to find a place to get an audtion.
    I do really find it unfortuantely though, that so many manufacturers insist on product headphones that emphasise the bass range far too much. It really drowns out details across the rest of the audio spectrum, leaving the resulting sound coming across as very dull, overly heavy and lacking in fine details.

    • http://www.headfonia.com/ Headfonia_L.

      Not everyone wants the same kind of sound, A lot of people find the 880 or 70X extremely boring. Same goes for amps, the O2 in example is neutral sounding, to a lot of people that means it’s boring.

      People will always have different tastes and as long as that’s happening there will be differen sounding gear. Nothing wrong with that

      • Peter Harlovic

        The thing that’s wrong with it, so to speak, is that many reviewers give better reviews to products that they describe as ‘warm’ as if this is an objectively superior characteristic.

        Likewise reviewers will often describe a headphone that has a +5db rise in the bass as having better bass…and then go on to label another product thats closer to flat in the bass as “lacking bass” when that’s absolutely blatantly wrong.

        Reviews really should be more objective – call a product what it is. If it’s got a rise in the bass, but you happen to like that, then call it that way. There is nothing wrong with saying “productX does exhagerate the bass region slightly which is great if you like a more bass heavy sound, but if you prefer a more accurate low end then productY is more suitable”.

        Its like when reviewers try to describe one product as “great for jazz” abd another “great for hiphop”. What is up with that? A product will colour all sound in the exact same way. If you’re speaker has a 5db peak at 4khz, then your product is going to have a peaky lower treble / upper midrange regardless of what material you play through it. People say headphones with more bass are better suited to rnb – why? If the artist wants excessive bass in their track, then they tune that in to the track itself. Headphones with +10db bass will just further overemphasise the ALREADY overemphasised bass region.

        Also the use of these terms “warm”, “dry”, etc is insanity – i have no idea who came up with these silly ‘audiophile’ adjectives, but they tell you nothing factual about the sound. Everybody’s definition of “warm” is different to the next person’s. When you say warm, do you mean that the bass has a softly rising response down low? Or do you mean the treble rolls off more strongly than most up high? Or do you mean both? Nobody knows. People use these terms in reviews for headphones, car audio, hifi, you name it. Yet the terms are almost meaningless due to the ambiguity of their definition.

        When casual audio people use these methods to describe things i let it pass, but when its hardvore enthusiasts, industry professionals, etc, then it’s just…a little frustrating to those who actually want to know what the real traits of the product are (as opposed to trendy buzzwords).

        • http://dalethorn.com dalethorn

          All very good points, but being purely objective (if that’s even possible), you’d be writing 5 times as much text to try to communicate to people who already are familiar with the review style and the adjectives used.

          The irony I see in this is that even in my own personal case, I’ll have a given headphone on hand for a long time – a few months to a couple of years, and at some point I hear it as rather warm, and a couple months or so later it may seem less than warm, as my current experience shifts toward warmer headphones.

          So going back to objective, I suppose I’d have to declare a certain headphone as the ‘standard’ for neutral, just for reference and all. But then, that headphone doesn’t sound neutral on all of my music. And so it goes…

          • Peter Harlovic

            But the if the headphone doesnt sound natural on all music, then its the music (not the headphone) that sounds unnatural.

            A natural audio system reflects the source, nothing more or less.

            Also frustrating is when people reply to a comparison like this I’ve for example, and then give their thoughts on the K701…based on their experience with the k712.

            These are two unique models, but little talk about them as of they are identical. Of you look at the measurements its clear that they are not. The K712 its way too heavy on the bottom end, the K702 is relatively neutrality low, and the k701 has a soft bottom end rise comparable to the k702, but doesn’t extend as low.

            So then i see people making comments like “the k702 lacks bass”, when in reality its about -3db at 30hz. For reference, that’s among the lowest any headphone will play at -3db.

            What These people really mean when they say it lacks bass, is that it doesnt overemphasise the bass – big difference.

            Many reviewers make such comments and it frustrates mean end because the consumers who read those reviews are going to potentially get the wrong impression.

            If like if reviewers were more accurate n their feedback. Instead of saying something sounds warm, just say the bass is a little over emphasised, and the treble doesnt extend especially high. Everybody understands what that means, and theres no ambiguity.

            I know it’s easier to stick to the cliche’s, but taking shortcuts wont always lead you down the right metaphorical path.

            • http://dalethorn.com dalethorn

              Generally I agree, and it’s your first sentence that makes the case, for the theory at least. But, what really matters is the extant music after all. Let’s try a small experiment: We have all the world’s music, which all sounds good to OK on headphone A, but one track is not OK on headphone B. Then that track is remastered (in a good way) and now all sounds good to OK on headphone B, but not on headphone A. If we can “prove” that headphone B is still the fault because we can easily measure the midrange coloration that’s the difference, maybe we can sell that to people. But if the problem is in the treble, we don’t have any flat curves to investigate that. So we look for tonality to see if that’s accurate. Then eventually we realize that it’s very complicated because everything has minor faults all over the place, and judgements shift with every track. So I have to learn the reviewer’s tastes and judgements, and measure the reviews against that. Otherwise, I’d be comparing a thousand points of detail with every headphone, and lose the forest for the trees.

    • http://dalethorn.com dalethorn

      I would say, in defense of ‘warm’ that’s not a specific emphasis, that with certain gear that have very small rough areas that contribute to a more clinical or ‘technical’ sound, an equivalent item (a headhone for example) that uses wood in the earcups can often smooth the sound creating a sense of being warmer.

      Pardon my use of imprecise phrases here, since I’m aware that simple frequency response is far, far from adequate to describe an item’s sound, or even a part of that sound known as warmness – there are so many technical aspects of sound that no review can cover them in less than 3 month’s work on each item. Innerfidelity covers a little of that with lab measurements, but it’s just a start.

  • David Whitbeck

    I’ve owned all three headphones at one time or another. Many of the comments made in this shootout I think are apt, but some are not.

    The dt880s have amazing bass extension. It is also the most accurate bass reproduction I’ve heard from a headphone (at least in the sub-$500 price bracket). It does not sound thin. In fact the bass is slightly elevated and colors the music. It is is not the upper bass that is elevated like in Sennheiser headphones but lower to mid-bass. Also the peaks in the upper-mids and treble provide this headphone with a very unique coloration. Also it is never sibilant, not at all. I’ve never heard another headphone that sounded like it.

    The q701s don’t have a “blank look.” They’re warm and dark, just not as much as Sennheiser headphones but enough that they are not quite monitor flat.

    The hd650s are indeed warm and dark, but I think that it is a head-fi myth that they are slow or need expensive amplification. They actually require the least voltage of the three headphones (based on sensitivity and impedance) and sound great out of everything but mobile devices. They are the warmest and darkest headphone of the three, but not nearly as warm or as dark as it is made out to be. They have top class detail resolution in the mid-range, I would say that it is the most detailed of the three.

    All three are close to but not exactly neutral, and are each delicately colored in their own unique way. All three are capable of impressive sound stage and imaging (for headphones anyway). All three require a desktop amp to sound their best. And all three are excellent headphones without any single one possessing a significantly improved sound quality in comparison to the other two.

    For any prospective buyer: please refrain from reading that article. It can’t tell you which sound signature you would prefer, only you can. And all three are very close to each other in quality. If you can afford it, buy all three, listen to them and then pick one and return the other two.