Thank you Sineaptic for sending us this headphone to review!

The process of reviewing products is largely a game of hit or miss. For every good product, I go through plenty of decent or mediocre ones. Once in a while though, I get the opportunity to review something truly special. Something that meets and exceeds all expectations. Most of the time, that good thing is good but expensive - after all, you usually get what you pay for. Rarely, you get something so good, and priced so well, that I can't help but scream from the rooftops: buy this before they fix it!

Enter the Sineaptic SE-1. Before I get into why I love this thing so much, I think I should explain some of its quirks and what makes it so unique. First, and most important of all, is the dual ribbon driver.

Most headphones (and speakers) use a dynamic driver; this is the common round cone you often see. Many higher-end headphones have started to use one of the flat driver technologies. These include planar-magnetics, electrostatics, and ribbons. The benefits are many, though there are some downsides. The benefits tend to include clarity and low distortion, primarily. The most common type of flat driver is called planar-magnetic. They sound quite nice, and I own two pairs: the affordable Fostex T50RP Mk3, and the mid range Monolith M1060. Both of them are modded to some extent to match my preferences. Electrostatic headphones are relatively rare; I own one of the most affordable ones, the Koss ESP/95X. They come with their own amp, because their design necessitates it; this makes them not at all portable, not to mention expensive. But they are known for incredibly clear sound.

That brings us to ribbon drivers. In some ways, they are both simpler than the others, but also used far less often in headphones. Ribbon drivers are thin pieces of aluminum foil suspended between two permanent magnets, and the current runs through the aluminum itself, generating a field that interacts with the magnets, then vibrating as signal passes through. They are known for impeccable treble detail. There are not many ribbon headphone drivers out there, and those that do exist are quite expensive; well over one thousand dollars. (Until now.) Ribbon drivers are sensitive to physical jarring, and require special amplifiers or large transformers, because the impedance of a ribbon driver is extremely low, and most devices and amplifiers can't handle that.

Rather than implement a single ribbon like the other big ribbon headphones out there, Sineaptic designed the world's first dual ribbon setup. In this case, there are two ribbons right next to each other per ear, making for a more symmetrical surface area, and the driver is easier to fit inside of a normal-sized headphone. Don't misunderstand - the SE-1 is still quite large. But they are around the same size as some of the planar headphones out there, rather than comically large like some of the other large single ribbon headphones I've seen pictures of.

In order to deal with the impedance and power requirement problems inherent with ribbon drivers, the SE-1 neatly sidesteps this issue by building the amplifier right into the headphone. This does mean that these headphones require batteries or some external power source, and thankfully batteries are built-in, and they charge via USB-C. Any use of the SE-1 does require using that powered amplifier though, so if you let the batteries die, you will need to charge them before use again. I've had that happen to me; thankfully, you can use them while charging, though it may look funny since the charging port is on the front of the left ear cup.

When taking a first look at the SE-1, well, it's definitely a unique beast. It uses dual suspension pads instead of a headband, which is an interesting choice. The only other headphone I tried with those was rather uncomfortable, but it works fine in this case. The ear cups are open back, which means sound from outside the headphones gets in, and sound from within the headphones gets out. Rather than a flat design for the outside of the cups, this one uses concentric plastic rings with ridges that stick out. This design might be for acoustic reasons, or perhaps it's just for looks; I can't say, but it's unique.

The materials used in the construction is all (or mostly) plastic. It's all a combination of black and dark gray, and it doesn't look bad, but the materials used do not feel premium to the touch. A lot of headphones trying to appear more premium use more metal and/or wood, which can feel nice, but sometimes it's also heavier. The SE-1 is quite comfortable to wear for many hours at a time. One area where they wisely used better materials is where it touches your head; the ear pads look and feel great, and use a combination of protein leather and fabric, which I personally prefer over the more popular velour, since velour makes me itch and these do not. The dual suspension pads also have protein leather pads, along with some kind of stronger foam or rubber underneath that supports your head well. Even after many hours of use, they don't press hard on your head.

While the feel of the materials is passable and seems a bit unpolished (it is their first product after all), it more than makes up for it in other ways. More on that in a moment.

As a first product, the manufacturer is new to making headphones. I discovered in my review sample that the phase of the drivers, in this case the electrical polarity, was mismatched. After contacting Sineaptic, it turns out I was the first person to notice this issue. Thankfully, he has adjusted the production line based on my feedback, so hopefully you won't run into this as a purchaser. However, if you do, I made a helpful video on how to modify the headphones to correct this issue.

One last thing I wanted to point out is that since these are self-powered, they might as well make the best of it, right? These are quite unusual in that they are open back, large, don't have a really tight fit, and yet support Bluetooth connectivity. The available codecs are SBC and AAC; while higher-end ones like LDAC and/or Apt-X would have been appreciated, considering their value pricing and focus, their decision not to license them is more than reasonable. If you need something that sounds better than Bluetooth, the 3.5mm stereo audio jack is always available, and recommended for serious listening or gaming for latency reasons anyway.

One really nice thing about their Bluetooth implementation is that it supports Bluetooth 5.2's latest feature, dual device. What this means is that you can pair and connect the headset to two devices at once, and both of them will show connected. If one take a call (or uses the phone call Bluetooth mode), the headset will lock into that device, and you can speak through the built-in microphone (it does have a MEMS microphone array, which only works when connected via Bluetooth). The microphone sounds pretty good, and works great for phone calls or other similar voice chats; I use it for Microsoft Teams quite often. I find that this dual connectivity Bluetooth is fantastic for work. At the start of my day, I hold down the power button for a couple of seconds, and hear the voice prompt 'wireless mode', and then each paired Bluetooth device connects, and I hear 'connected' as each one connects. Then, I can listen to a podcast or some music via my phone as much as I like, until it's meeting time where I can quickly jump on a call and expect the microphone to start working right away. I use this feature every work day and it's incredibly convenient.

And being a remote worker who gets the house to myself, being open back is kind of nice. I can hear it when the dogs bark, if the phone rings, or any other outside event while listening to whatever I am. I can even just play something on normal speakers and still hear them with the headphones on. This of course makes them worthless for traveling, but that's okay; one can always use earbuds or a noise-canceling set if you need that. But for when I'm home, these things are amazing.

It also helps that if you plan on traveling and still want open back audiophile headphones, they include a nice hard carrying case. They ship this case with the headphones inside in a box attached to the corners, and suspended by four rubber bands; the box literally 'wobbles'! I've never seen packaging like this; it's quite creative. This also means that it can handle the toughest aspects of shipping just fine. This shipping impact resistance means that even if the box is so damaged it has a hole in it, the headphones are probably going to be just fine. Ribbon drivers in general don't take big impacts well, so this is a very smart decision on their part to keep returns down.

When you plug in a 3.5mm cable into the bottom of the left ear cup on the headphones, if you have Bluetooth enabled you will hear the voice prompt 'auxiliary mode' and it will disconnect from your Bluetooth devices. While Bluetooth sounds quite good, 3.5mm mode is lossless, and sounds as good as is possible with this headphone. It's also latency-free, which is better for gaming applications. Interestingly, auxiliary mode is also how you power it off when you're not using it; I'm not sure how the cool down works, but if no signal is going through the headphones, it powers off silently (if you want to be really sure, unplug everything from it). If you want to use it as a wired headphone, just make sure something is plugged in, and that's it; unless the battery is dead, it will start playing something without you pressing any buttons. In some ways it's incredibly intuitive, but if you don't know you need to charge the headphones even with wired operation, it could shut off when you don't expect it. I find that charging it every two days of normal use seems to work for me. If you use the headphones morning until night, you may need to charge it in the middle of the second ay, but that isn't too common. I use these things nearly constantly, and the two day charge plan works great for me.

While batteries in a wired headphone may seem strange, the good news is that it uses two industry standard 3.7v 14500 Lithium-Ion cells. While these are not meant to be opened by end users, let's just say that if you had to replace the batteries, you should be able to with only basic electronics skills needed. And the batteries are cheap. As of this writing, you can easily pick up a pair for under $20. That they chose to use industry-standard parts makes me far less worried that dead Lithium-Ion cells will long-term make this headphone worthless.

Which is a good thing, because they sound absolutely incredible, especially with instrumental music. I must point out that while active, the headphones' built-in amps do have a very quiet, low-level hiss. Outside of that, these ribbon drivers expose virtually every detail, reveal every scratch or rib of the instrument, and every breath of the musicians. Well-recorded music will treat you to an audio feast that most listeners aren't used to. You need a very expensive audio system or pair of headphones under normal circumstances to get this level of detail retrieval - it's truly impressive! It's hard to overstate how incredible these things sound, especially with the right kind of music.