If you’ve heard the HD800/S then you should have a pretty good idea on how the HD8XX performs technically. Top-class resolution with some of the widest (some say the widest) soundstage in a headphone are the prime reasons why the HD800 series still remain relevant more than 10 years since their release in 2009. You’re not expecting much, I’m not expecting much, so let’s just rip the band-aid off. Obviously, the sub-bass response of the KSC75 is its biggest weakness that cannot be fixed with mere EQ, so don’t get one if you value dat rumble in your music. Disclaimer – The product was provided to me free of charge for the review in exchange for my honest opinion. Also I'd like to mention that I think the HD6XX is still a good headphone. Also that the difference was so strong most likely because I don't put in the effort to listen. Still tho, it's impressive that I don't have to try now. Also sorry about the long post.

So they won’t give you the isolation from the outside world. If you can get along with this, you can get this headphone. But if you prefer isolation over sound quality, this headphone is not for you. Despite the great sound quality, you will face trouble using it in places with noises.

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The separation on mids and bass is average. I found it not enough, and it contributes to a poor sense of detail. I could hear all parts of my music though; think of it like a fuzzy picture. Sound bleeds together even though its all there. The treble escapes this poor separation however.

Summary – HD6XX has a very natural, well-balanced, warm sound signature with very good tonality and timbre of instruments. It has a mostly neutral bass presentation except for a minor sub-bass roll-off around 40Hz and a tiny 2-2.5dBs boost in the 80-200Hz range. It has extremely well-done midrange which is its main USP; it being linear, neutral and almost perfectly tonally accurate. Lower treble is natural, easy to listen to without any harshness or sibilance. Upper treble extension is fairly good with a prominent peak at around 15kHz. Overall, HD6XX is one of the easiest headphones to get along with because of how natural, comfortable and well-done the sound signature is. I bought HD 6xx in Nov 2016. Before I got this, I already got ATH AD1000x, ATH M50x, and Massdrop X AKG K7xx. So I will compare HD 6xx to these three headphones. Four years ago there was even a meme on the then-fabled HD8XX (with an entire saga between said memer and Massdrop thereafter), and years after that the masses continued clamouring on and on for the HD6XX-equivalent to the HD800. For years the community heard nothing… right up to the beginning of 2021. In the way of raw fidelity, the HD6xx scales so much with superior gear that it makes it the better overall value for audiophiles. The HD58x is the better value for casual listeners who don’t have an expensive rig. These have a pretty solid soundstage, much bigger than your typical closed headphone. They definitely excel with any kind of acoustic music. I have also found that they're great headphones for tuning a system because it's very easy to hear changes in the system and make sense of them. Very balanced sound.I wouldn’t have any second thoughts of getting rid of the 660s, but the 600 and 6xx… I don’t ever want to part with either. A truly legendary headphone series for a reason. I can absolutely see why some may prefer the HD600 over the HD6xx, and I love them both. However, I could absolutely do without the HD660s. I've never truly loved them, but hearing the other two made me disappointed in the HD660s even more. I don't regret buying them, and they served me very well, but... I paid at least double for them and the return on investment just isn't there. Live and learn! On lower end gear, the gap between quality overall in bass between these two is not significant at all and sometimes feels too close to call which is objectively cleaner. The HD58x Jubilee has very low to end of moderate levels of bass quantity and doesn’t respond very well to bass boosting. If you are a basshead, grab a set of JVC SZ2000’s, haha!

Do note that unit variation may potentially be a thing here, some reviewers have gotten units that have quite a bit more treble than what I listened to.) It’s easy to regard the HD 6XX’s sound signature as just another dynamic-driven headphone, bringing with it traits that often have audiophiles drawing lines in the sand between those who love a drop of pleasing warmth in their sonic coffee, and those who demand near-clinical dedication to the recording as it was originally rendered. However, what is so pleasing about the HD 6XX (and the 650 before them) is that these headphones offer a pleasant mixture of each, for a best-of-both-worlds scenario. Bill Roberson/Digital Trends And there is another problem. As discussed earlier, it isn’t good enough for mobile phones. But for also portability reasons you might want to use it with computers only. So if you only want to use a headphone in your room to enjoy music with great sound quality, then this is for you.After listening to one slow ambient song, that usually felt ominous and intense as the plodding bass increased in energy feel pleasant and mild, that sealed the fate of the HD6xx as being labeled unengaging by me. The potential dealbreaker here is in the treble response. With its neutral lower midrange and relatively light note weight, its 5k-ishHz boost gets a little intense and harsh at times. Now you’ve probably already read some impressions on the HD560S and this peak; some say it’s completely benign and not worth the worry. Others claim it’s the worst thing in the world and will pierce your ears with the might of Zeus. And if we talk about the bass sound, it’s so rigid and warm, and the midrange sounds also dip close to the glowing colors of analog tape saturation.

I got these because I had the DT 880 and wanted soemthing that was darker while still being neutral and not too expensive. These were recommended to me as fitting that bill and also being similar to the HD650, so it would also give me a chance to hear what others people frequently reference. That is one of the main reason I bought them as well, they were something tons of others have tried and I could compare my opinion to theirs to get a good internal reference. I used them with the CEntrance DACport HD. In this headphone, the little unevenness there is in high-frequency sounds causes mostly by similar sounds and cymbals, with which one will get used to soon. The transients are well defined and crisp, and their decay into ambiance happens naturally. Disclaimer: The Massdrop x Sennheiser HD 58X Jubilee was sent to us a sample in exchange for our honest opinion and does not have to be returned. We thank Massdrop for this opportunity.I feel cheaper IEMs are competitive with this headphone in terms of detailing and tuning; at the bare minimum, excel at sub bass.