Last year I did headphone recommendations, and at the time thought it would be an unusual thing. As it turns out, last year's big pick (the Monoprice Monolith m1060 v2) is still a great choice for someone who wants an open-back planar headphone. If you bought those last year and you're happy with them, stop reading now.
This year Massdrop delivered two collaborations which resulted in amazing headphones, but at wildly different budget points, so I'm going to recommend them both depending on what you want to spend. They're both open-back dynamic headphones. The downside to being sold on Massdrop is that you might have to wait to get them, and they're not offered on a traditional retailer like Amazon. As of the writing of this post, both headphones are in-stock at Massdrop, and ship within 1 business day.
Sennheiser is a well respected named in headphones. You can spend anywhere from $15 and $50,000 on a pair. They run the gamut of audiophile headphones, gaming headphones, wired and wireless, open- and closed-back, on- and over-ear, and even in-ear monitors.
The HD 58X Jubilee is a collaboration between Massdrop and Sennheiser which is technically part of that 600-series family. It has the same basic styling, and the excellent comfort that these headphones are known for. What's different here, though, is that at $150, they perform well above what you'd expect for the price. Even better, with 150 ohm impedance and 104 dB sensitivity you will mostly be able to use them without an amplifier (though I always recommend one). They are open-back, with just a slight amount of damping, so you'll be able to hear most of what's going on around you...and everybody else will be able to hear what you're listening to. They open up a bit more if you remove the foam from behind the drivers (a tweak I strongly recommend you try, as that improved the quality of the treble for me, though some have complained that find the resulting treble to be too bright). The mod takes just a minute or two to complete (pop off the outer ear cup, remove the foam, and replace the cup), so I recommend trying it both ways.
The sound signature to me sounds "W-shaped", which is to say that it's reasonably balanced, with a bit of emphasis on all of bass, mids, and high end. The bass is tight, fast, and plentiful; all but the most ravenous bass heads will be happy with the sound here, and more discerning listeners will appreciate it as well as it's never overpowering. Vocals are excellent, especially female vocals. The high end felt slightly veiled to me with the foam in place, but it really opened up for me with the foam removed. A song like Crazy, Classic, Life by Janelle Monáe really shows what these are capable of. They are a fun pair of headphones, for sure. Sound stage is fairly narrow, creating an intimate listening experience. This also makes them an excellent choice for gaming. Detail is very good, and you'd probably need to spend $500 on the HD 660S to get noticeably better detail out of the 600-series family.
Build quality is typical for the Sennheiser 600-family series headphones. They are predominantly plastic with porous metal mesh cups protecting the drivers. The pads are a stiff padded velour (not memory foam), with Sennheiser's signature oval shape which generally matches the shape of ears better than round pads. The band is also plastic, with the portion coming into contact with your head having a 2-segment pad which feels like less dense foam wrapped in a synthetic material that's almost Spandex-like. It has strong clamping force out of the box, so there's no risk of these falling off your head. They are very comfortable for long-term wear. It comes with a single removable cable terminated in 3.5mm single-ended stereo, with a 1/4" single-ended stereo adapter. The cable is a good quality rubber-insulated dual-wire arrangement.
Honestly, there is no other headphone I'd recommend between $25 and $250.
I love music. It's a constant part of my life. While I listen to a lot of music on speakers, there is still something special about music through headphones. These are my "end game". They are my first choice for recreational music listening in all genres.
Focal is a French company that is better known for their speakers than headphones, and in the U.S. is a name most people won't recognize. The Massdrop x Focal Elex is another collaboration between Massdrop and a headphone manufacturer, and although they may seem expensive at $700, they're actually at the low end of their headphones (which goes all the way up to the Utopia for $3000). They are even more open than the HD 58X: I cannot tell the difference listening to ambient room noise with them on or off. With 80 ohm impedance and 104 dB sensitivity, you can use these with your portable device, but it would be almost criminal not to give these a proper amplifier (even while portable).
The sound signature of the Elex is actually remarkably like the HD 58X: energetic and engaging, with emphasis that sounds slightly "W-shaped" to my ears. The difference here is that the drivers are simply better at doing everything: the bass is faster while reaching lower into sub-bass, vocals are angelic from both male and female singers, and the treble is crisp and accurate. The level of detail achieved here is frankly astonishing, and this the kind of listening experience that even hardcore "meh"-heads would be able to acknowledge is better than their headphones. At this price, it better be. If there's any complaint, it's that the treble can sparkle a little bit at high volumes, though you can drive these things to insane levels without distortion (save your ears and don't). The sound stage on these is very wide, making you feel like you're sitting in the middle of the performance stage. In short, it's my perfect headphone. I've listened to things that are more money, and things described as more accurate, but they often fell short for me by being too clinical and boring (Sennheiser HD 800, I'm looking at you).
There is no better word to describe the Elex build quality than "tank". The driver enclosure is a thick, strong plastic, with a metal mesh covering the drivers. The connector and head band adjuster is a very sturdy metal, with a unique spring mechanism to help the headphones clamp to your head. The pads are an incredibly soft, with a deep and large opening, utilizing slow acting memory foam wrapped in what feels like perforated Alcantara. The head band is wrapped in protein leather on three sides and the same Alcantara material on the contacts the head. The breathable pads make long listening a joy. Clamp force is on the weak side for a headphone of this weight, so there is quite a bit of sway when shaking my head. I wasn't concerned about them falling off, but they also didn't feel stuck to my head like the ultra-light HD 58X do. They come with two six foot long, fairly stiff cloth wrapped cables, one terminated in 1/4" single-ended stereo, and one terminated in 4-pin balanced stereo XLR. The stiffness of the cables isn't great, but it isn't a breaking point (and you can easily pick up something third party like Periapt, which offers good quality without breaking the bank).
Are these worth $700? Absolutely, if you've already committed to the idea that you'd be willing to spend $700 on any headphone. They are my best recommendation for anybody looking in the $500-$1000 range. Just remember to set aside an extra couple hundred dollars for a good quality amp (see my list from last year, or check Massdrop to see if the THX AAA 789 is available).
Is spending this much on a headphone crazy? Maybe, but keep in mind that a good pair of headphones will last many years, if not decades. In my mind, it's easier to justify a purchase like this that may bring you many years of happiness than it is for people who get a new $1000+ phone every 12-24 months.