Having tested all the main competitors (AKG K240 Studio, Audio-Technica ATH-M20x, Audio-Technica ATH-M30x, Audio-Technica ATH-M40x, Audio-Technica ATH-M50 (the old version without the letter “x”), Audio-Technica ATH-AD700, Beyerdynamic DT 770 PRO 16Ω, Beyerdynamic DT 990 PRO 250Ω, Sennheiser HD 25, Sennheiser HD 560S, Sony MDR-7506, and Yamaha HPH-MT5), I settled on the Sennheiser HD 280 PRO as the best in nearly every category.
Build quality: Yes, the HD 280 PRO are made of plastic, but they are made really well. In (stereo)typical German fashion, everything has been thought about: there are ball bearings in the size adjustment mechanism, and the notched size positions help you remember your setting; there are also miniature rubber “bumpers” on the yokes (for those who do not know, yokes are the fork-shaped parts securing the earcups to the headband) that prevent the earcups from hitting the yokes and making an annoying plastic-on-plastic clank (all you can hear is a soft, satisfying thud); the headband has a notch in the middle, which helps prevent a hotspot in the middle of the top of the head, which some people experience after prolonged use; earcups swivel for when you want to look cool and wear them around your neck, or when you simply want to put them in your backpack. Summing up, if HD 280 PRO were a car, they'd be an old Mercedes-Benz, a marvel of engineering where even the sound of shutting the door is oddly satisfying. Although, as they say, beauty is in the eye of the beholder, I have to admit that when I first saw these headphones, my reaction was similar to that of many people. I thought, “Dear God, this must be the ugliest pair of cans I have ever seen!” However, once I did some research and understood their function-over-form design, I came to appreciate it a lot, and I now even find them rather beautiful... The only criticism I have is that the coiled cable is a little on the heavier side, and it had a couple of kinks due to the way it was packaged. I wish manufacturers would coil the headphone cables instead of folding them... Finally, for those who care about these things, my pair was made in Romania.
Comfort: It is difficult to find a balance between headphones that stay firmly on your head and the ones that you can wear for hours without any discomfort, but HD 280 PRO manage to do both things perfectly. Out of the ones I have tried, they were the most comfortable. The earpads are big and soft and adapt to the shape of my head almost instantly, after which they feel like two fluffy pillows. They are so comfortable to me, that I sometimes wear them without plugging them in! When I was doing my research, I found a few warnings that their supposedly heavy grip might even cause headaches! However, it has not been the case for me personally. For reference I will say that my head is about average, perhaps, a bit on the larger side. In regard to the headband, again, no complaints whatsoever. The only downside to that close pillow-like fit is that my ears warm up a little faster than with some other headphones, but the difference is almost negligible. The only headphones that came close to the HD 280 PRO in terms of comfort were the Audio-Technica ATH-AD700. They fit so lightly that one could easily forget that one was wearing them, but they did not stay put all that well whenever I bent down to pick something up off the ground.
Noise isolation: Nothing came close to the HD 280 PRO! They seem to isolate outside noise even better than the industrial foam earplugs I use for sleeping. I could barely hold a conversation with a person standing next to me! Of course, that might be bad in some cases. It depends on individual preferences.
Sound: Sound is a highly subjective topic because the shape of everybody's ears is a little different, and so are each listener's preferences. Also, one pair of headphones may sound a bit different from another due to the width of the range of tolerances allowed in manufacturing. Having said that, at least to my ears, my HD 280 PRO are mostly “flat”, with a very slight bump in the lower frequencies. I mostly listen to old pop and jazz, and the particular frequency that is ever so slightly boosted, renders the sound of an upright bass especially pleasing. In regard to the upper frequencies, the usefulness of my review will be limited. Being 31 years old, I cannot hear sounds that have a higher than 17 kHz frequency all that well. All I can say is that neither the acoustic guitars nor the cymbals sound harsh, and the sibilance (again, to those who do not know this, it is the annoying hissiness of the letters “s”) is very slight, if any at all. The soundstage (the size of the perceived space, in which the musicians appear to be playing) is not as big as that of the Beyerdynamic DT series headphones, but it is not always a con. I might be in the minority, but in music centered around vocals, I usually prefer a more intimate listening experience, when a singer seems to be just a meter or less in front of me. Julie London's album Love on the Rocks is perfect for that! However, put on some Bill Evans Trio, close your eyes, and you'll be surprised how convincing the experience of sitting in some smoke-filled jazz club in New York is! And here we get to the imaging (the ability to determine the location of each and every musician in that perceived virtual space), which, at this price range especially, is plainly and simply excellent!