Hands-On with Blue's Mo-Fi Headphones: Comfort Married to High Fidelity

Earlier on Tuesday, Blue Microphones announced—finally—Mo-Fi, professional quality headphones for audiophiles and musicians. The company gave us this maddening, teasing not-quite-a-glimpse back at CES in January, and I've been waiting eagerly since. Fortunately, Blue gave me early access to them, and this review is based on hands-on and ears-on testing for the last two weeks.


Mo(bile)-Fi(delity) by Blue Microphones

What Mo-Fi Is

Mo-Fi are over-the-ear headphones aimed at audiophiles and musicians who want a high fidelity experience. Listen to vinyl, and not because it's ironic? Is it lossless or nothing for your digital files? Do a lot of music mixing on-the-go or at your desktop? Mo-Fi is for you.

They offer a nominally flat listening experience, rather than a tuned experience like Apple's bass-heavy Beats brand. Because they are nominally flat, you're hearing more or less what the source material sounds like.

You'll find some early reviews out there focusing on Mo-Fi as a mobile-listening solution. My review focuses on the target market for Mo-Fi, audiophiles and musicians.

Fit and Feel

Before I get into how these sound, please allow me to wax poetic about how Mo-Fi feels. Because, seriously, no headphones have felt so right on my head. In fact—and I'm OK if you decide at this point that I am completely bonkers—I feel safe when I have my Mo-Fi headphones on.

I know, it sounds ridiculous, but it is absolutely true. I suspect it's related to the swaddling effect, but the way Mo-Fi grips my head is comforting. I have worn these for up to 4 hours in a stretch, and I've never felt any fatigue or discomfort from doing so, and that is really saying something.

So let's talk about Blue's approach in making Mo-Fi. The headband is not a headband; it's a four bar linkage system. Most headphones use a spring-loaded band to grip your head, and some do a better job of that than others.

The top of Mo-Fi

Note the Tension Knob for increasing and decreasing the tension

If you look at the photograph above, you will see that there are two hinges across the top, and all that business with those side trusses is part of the (patent pending, FWIW) four bar linkage. This not only eliminates a stress point that many headband-headphones have, it helps them sit more comfortably on your head.

The cups are suspended from a pivot-arm (it makes me think of a dog's knee), not a slider. This helps keep the cups even, but more importantly, adjusting the position of your earcups won't affect the tension in the four bar linkage system at all. That allows the headband portion of Mo-Fi to remain at an optimal tension at all times, which is good for wear and tear, as well as comfort.

Most importantly, all this stuff gives you a good seal, no matter the shape of your head and position of yours ears.


Mo-Fi is heavy, a bit more than a pound heavy, thanks in part to the built-in amp. The solid construction of the four bar linkage system and the 50mm drivers also adds to the weight. Personally, I felt that heaviness when holding or carrying Mo-Fi, but I did not feel it when wearing them on my head. Your mileage may vary on this front.

But they also don't fold up very much. That makes them awkward to carry, despite the emphasis on "mobility" in the Mo(bile)-Fi(delity) name. I suspect that people who highly value the flat sound and the amplified volume won't mind, while those who don't will find them cumbersome.

Next: Amp, Battery, and Modes

Page 2 - Amp, Battery, and Modes


Blue built an amp inside Mo-Fi. It's a 240 milliwatt amp with a frequency response from 10Hz to 20kHz. It's analog circuitry, and its job is to boost the signal, not process it. Blue adamantly and repeatedly stressed that the amp is not doing any digital signal processing (DSP) to the sound, which is why the frequency response is nominally flat.

The amp was designed specifically to go with the 50mm drivers in the headphones, and it helps Mo-Fi offer you the same listening experience across all devices. That's because not all sound processing was created equal, and it's something musicians might appreciate the most. Whether you're mixing on your iPad, your laptop, or a desktop computer, you're going to be hearing close to the same thing.

Blue says this amp offers up to six times more power than "typical mobile devices," and it definitely makes them louder than un-powered headphones.


There is a rechargeable battery inside Mo-Fi, the better to power the amp. It has a capacity of 1,020mAh, enough for 12 hours of listening. My unit is still new, but I've gotten more than 13 hours out of two charges, which tells you how much testing I've been doing in the last two weeks. Also, your mileage will vary.

It charges via an included micro USB cord usable with any USB port, including chargers with USB ports. The company recommends not charging and listening at the same time. The image below shows the sound jack and the micro USB port.

Ports and Jacks

The switch mentioned earlier is indicated by the orange stripe

One of the most clever things Blue did is design Mo-Fi so that they automatically turn off when you take them off. That maximizes battery life and means you never have to deal with remembering to turn them off. If you've ever forgotten to turn off your headphones and discovered them dead the next day, you will so appreciate this feature.

Indicator Lights

The indicator lights on this thing are subtle, and I like that. Inside the outer grill is a not-very-bright LED that glows when it is charging and when it's turned to On or On+. Nothing glaring, nothing screaming "LOOK AT ME I AM HEADPHONE!"


Mo-Fi has three modes via a switch that is very easy to access when you have your Mo-Fi on. The first position is Off, which is a passive mode that doesn't require battery power. This means you can use your Mo-Fi even if the battery is dead, which isn't always the case with battery-powered headphones. In Off mode, Mo-Fi won't be nearly as loud as it is in powered modes because, you know, no power.

On is the base powered mode. This activates the internal amp, which boosts the sound. The drivers have a frequency response from 15Hz to 20kHz (that's less than the 10Hz-20kHz range of the amp), and Mo-Fi is nominally flat across the entire range.

On+ activates the amp’s analog low-frequency enhancement circuit, meaning it boosts the bass. In more technical terms, On+ offers a 4.5 decibel increase at 60Hz, for what Blue describes as "a very subtle bass enhancement."

In other words, even in On+, Mo-Fi is not competing with Beats for what Blue called the "bass-in-your-face" experience. On+ boosts the bass without letting the bass take over your headphones.

For listening enjoyment, I found myself favoring On+. When I was working with multitrack songs in Logic, I stuck with On. And really, the quality of your source file matters a lot. Songs that were mastered in a way that favors the low end won't get much boost from On+, and low-resolution files are going to sound like low-resolution files no matter what you're listening through.

Tip: Turn the volume on your source device down before turning Mo-Fi to On or On+. The onboard amp is not a gimmick—it is seriously much louder than the passive Off mode.

Next: Sound and Conclusions

Page 3 - Sound and Conclusions



Mo-Fi sounds great, but I want to stress that people who think Beats sound great aren't likely to appreciate Blue's Mo-Fi. My testing included a lot of 5-star playlist in shuffle mode while writing, in addition to my test listening list.

The sound is warm, but more importantly it's accurate. The bass is solid, but not overwhelming. Mids and highs are crisp, without ever being tinny or shrill. With Mo-Fi, I hear everything in the song. Every instrument is in its place, and each frequency is offered in proper proportion.

I love that.


I can't get enough of these things, but they're not my favorite pair of headphones for pure music listening. My V-Moda Crossfade m100s are because they are tuned so exquisitely (I reviewed the Crossfade M100s last year).

But they are my favorite headphones for writing because they're so comfortable and because of their superior isolation properties. They're also my favorite headphones for podcasting, making phone calls from my desk, and hands down for recording and mixing music.


Look at the padding on the headband!

I'd probably take my m100s to a coffee shop when I was in a hurry just for the sake of portability, though I tested Mo-Fi at a noisy-as-all-get-out Starbucks for this review. On a plane? I'm taking Mo-Fi. No question. And at home, it's all Mo-Fi unless I am focused only on listening to the music.

I mention these things to give my review context. I'm lucky that my job gives me a choice in high-end headphones, but most folks don't have that choice.

The bottom line is this: if you're an audiophile or a music professional, you should give Mo-Fi a listen. I think you'll love it.

If you're a music fan—especially pop music—who is ready to plop $350 down on a pair of great headphones, listen to Mo-Fi, something from V-Moda, Beats, Sol Republic, or one of the other brands competing on a tuned experience. You may choose one or the other, but it's going to depend on your frame of reference and your listening tastes.

Product: Mo-Fi

Company: Blue Microphones

List Price: $349.99

Vendor Price: $349.99



Insanely comfortable, with a design that ensures a great fit and a better seal. They look cool, though not at all subtle, and they sound amazing. The built-in amp offers a great listening experience that will be louder than most mobile sources. Mo-Fi offers a flat sound ideal for audiophiles and musicians.


Cumbersome to carry—they don't fold up into a smaller size. Some people will find them heavy, though they were sheer comfort when sitting on my head.