Sennheiser HD6XX: The Critical Take
Obligatory “not an IEM”, but I’ve received a number of requests asking for more headphone reviews. This is the next installment to my series of critical headphone takes, this time taking a look at a more entry-level audiophile headphone.
The Sennheiser HD6XX was the first headphone that I purchased two years ago, and incidentally, the last one to date. I bought it because I was a newbie, it was r/headphone’s golden child, and I wanted to buy the “correct” headphone. We’ve all been there, right? Unfortunately…I wasn’t a fan. They effectively sat for months at a time in a desk drawer, occasionally being popped out to try on new sources, then promptly being shoved right back in. I can already feel those pitchforks coming out, so I need to disclaim that the reviewer in me completely understands why the HD6XX is the default headphone recommendation for $200. My aim is simply to offer an alternative, more critical perspective as to why I’ve never jived with this legendary headphone.
Bass. I’ve often stated that “the HD6XX has no bass” and - jokes aside - I do believe there is an element of truth to that. While taken as a whole the HD6XX’s bass shelf is what would be considered nearly flat to most listeners, there is a noticeable roll-off once one goes under the ~50Hz frequencies. The HD6XX’s bass neither rumbles nor does it punch then; it’s in that neutral spot with which it’s simply dead boring. It’s fair to note that this is simply a limitation of most open-back headphones; however, the HD6XX’s bass fares no better in the intangible department. Bass texturing is barely passable. Furthermore, there is little sense of “bounciness” - indicative of a transducer scaling gradations in volume, akin to what one hears on a biodynamic headphone like the PhilPhone - to the HD6XX’s bass. In general, I get the impression that one would require a severe aversion to bass in order to deem the HD6XX satisfactory in this department.
Yet, it’s exceedingly rare to find a midrange done justice when it comes to headphones, and the HD6XX’s midrange is exactly that to my ears. I’d go out on a limb and suggest that it’s even better than HiFiMAN’s standard midrange tuning, one of the few headphone midranges that I consider palatable. The HiFiMAN midrange can sound slightly forward and lacking a sense of richness at times due to a subtle recession at around 1-2kHz. By contrast, the HD6XX’s midrange generally hits more neutral-relaxed with the pattern of decay equally close to spot-on, perhaps just a tad too elongated. If you’re going to buy an HD6XX for one reason…in my humble opinion, it should be for this. Of course, it’s still not a perfect midrange. While sibilance is never an issue thanks to a gentle slope off of 3kHz, indeed, I feel that the HD6XX is almost too recessed in the 4-6kHz regions. Instruments like electric guitars and soprano vocalists are lacking that last leg of bite in conjunction with the HD6XX’s limited resolution; mind you, this comes from someone who prefers a more relaxed upper-midrange.
The general recession leading into the lower-treble also partially begets the infamous Sennheiser “veil”. Percussive hits and finger snaps come across lacking an initial sense of crack and generally sound quite dull. This lack of zest mostly applies to the mid-treble too. But your mileage will vary regarding the upper-treble of the HD6XX, as it is dependent upon the wear of the headphone’s pads. Older, more worn pads will mitigate extension and lend to a smoother top-end. This is what I hear with my unit, as treble takes a nosedive after around 13-14kHz. In any case, the HD6XX’s treble can be summarized as “inoffensive” if only by virtue of it having very little to begin with.
Power memes, source memes, and scalability memes aside, technical performance on the HD6XX is generally middling to my ears. It’s fine for $200. But there’s a noticeable gap between the HD6XX and $500 forerunners such as the HiFiMAN Sundara. This is most apparent, first, when it comes to resolution. The mostly non-existent treble of the HD6XX neuters perceived detail up-top, and there’s a rather noticeable blunting to transients in the bass and midrange.
This blunting seemingly neuters the HD6XX’s perception of micro-dynamic contrast. Individual instrument lines generally sound smeared and, as I alluded to earlier, slightly too elongated to the way they taper off. For macro-dynamic contrast, too, the HD6XX noticeably lacks a sense of punch and incisiveness when a track explodes in volume. Some might argue that this is attributable to the lack of sub-bass and lower-treble; however, I’d counter that this is beside the point. Perceptively it is not there, and the HD6XX sounds about as flat and flabby in terms of dynamics as it does frequency response. I have never found my head bobbing to music ( fine , outside of maybe the first few times I listened to it), nor do I ever find myself messing with the volume knob.
If I had a dime for every comment I’ve read from bright-eyed Redditors raving about how instruments sound oh-so-precise and distinct on their HD6XX, I’d be a rich man. And coming from IEMs, I must admit that the HD6XX sounded rather “open” to me on first listen too! Unfortunately, further listening experience evidenced that its imaging chops are within the realm of mediocre. You hear the term “three blob imaging” thrown around quite often with IEMs (rightfully so), and the HD6XX is basically the epitome of it in the headphone world. Instruments panned to the corners of center stage come across closer to 0 and 180 degrees, mushing into instruments that should be in the side channels. And do we even need to talk about center imaging? Center stage comes somewhere from the back of my head, distinct from the sides. I find my eyes crossed inwards trying to pinpoint vocalists in center stage. It follows, of course, that the HD6XX is fairly closed-in for staging, especially for an open-back headphone.
So who is the HD6XX for? Clearly, if you’re after bass, treble, or imaging chops, you should be prepared to look elsewhere. But while I wouldn’t be caught dead listening to it for pure enjoyment - for me at least - it’s still the benchmark for which anything in its price range is automatically held to. For other listeners, I wouldn’t bat an eye at it being even more than that. Especially for listeners indexing for an inoffensive listening experience and midrange tonality, the HD6XX presents an ideal first choice of headphone.
