Specs at a glance: Blue Ella Driver Type Planar magnetic Impedance 50 ohms Passive, 10 ohms Active Frequency response 20Hz-20kHz Amplifier Output power: 250mW

THD+N: < 1% (94 dB SPL, from 20 Hz to 20 kHz)

Frequency response: 20Hz-20kHz

SNR: >101 dB

Noise: < 20 uV Battery 1000mAh Weight 481g (16.97 oz) Size Outer dimensions (closed): 21cm x 14cm x 12cm

Outer dimensions (open): 18cm x 29cm x 12cm Other perks Soft carry case

1.2-meter audio cable with Apple iPhone/iPad controls and microphone

3 metre audio cable

3.5mm to 1/4” adaptor Price £675 / $700

Planar magnetic headphones, which use a thin film suspended between neodymium magnets to deliver sound quite unlike that of typical dynamic and balanced armature headphones, are traditionally the reserve of the well-heeled audiophile. The sound quality is, according to fans, clearer, sharper, and more detailed and only surpassed by electrostatic headphones, which use electricity instead of magnets to vibrate a thin film to push sound to the ears.

Both technologies are more complex to manufacture than traditional dynamic drivers, and both require more volume to function. The result is that planar magnetic headphones like those from US-based MrSpeakers cost well over £1,000/$1,000, while the headphone amps required to drive them cost hundreds if not thousands of pounds more on top.

Blue, famous for its line of podcast microphones, hopes to make planar magnetic technology less intimidating with its Ella headphones (buy here). At £675/$699, Ella is hardly cheap (and there are sets like the Oppo PM-3 that are cheaper at £350). But they combine the coveted headphone technology with an internal amplifier (250mW) that allows them to be used with everyday devices like smartphones and laptops, as well as with a high-end audio setup.

Having had the privilege of listening to a set of MrSpeakers' top-of-the-line planar magnetic headphones—pumped through $10,000-worth of playback gear no less—as well as Ultimate Ears' £1,300 six-driver UE18+ custom earphones, I can confirm that Blue's Ella headphones sound excellent.

You do have to get over Ella's looks, though. Planar magnetic headphones are large at the best of times, but Ella's ostentatious styling merely exacerbates the "I'm an audio nerd" look. Ella sports a unique offset hinge, which sticks out behind your head, allowing for adjustment of height without the need for an extendable headband. A separate spring-loaded mechanism expands the headphones outwards, but remains taught enough to keep them firmly on your head. Despite their looks, the Ella headphones are easy to put on and comfortable, with thickly padded ear cushions and headband helping to distribute their substantial 481g weight.

That's far heavier than already heavy planar magnetic headphones like MrSpeakers' Ether, which tip the scales at 370g. While the mechanism, ear cushions, and headband certainly take the sting out of Ella's weight, they can only do so much. These are not headphones that, despite the internal amplifier making them easy to use with smartphones, are easy to carry around, or wear for long periods of time. Despite being closed rather than open back headphones, they don't offer the best noise isolation either, meaning that you have to crank the volume when using them in a noisy office, at which point they suffer from sound leakage.

Elsewhere there's a removable cable, along with a micro USB port for charging the internal amplifier, which is good for around 12 hours of listening and offers standard and bass-boosted modes. Should you run out of charge, the headphones will still work, but you're at the mercy of the device you've plugged them into—and the vast majority of consumer devices simply don't have enough wattage in their headphone amps to drive them at a reasonable volume. This is one of the major downsides of planar magnetic technology and why the tech has thus far failed to resonate with mainstream listeners, aside from price, of course.

The benefit is sensational sound quality. Planar magnetic drivers work by pushing an electrical current through traces embedded in a thin transparent film, which is usually made from Mylar just a few microns thick. That film sits between two magnets, one positively charged, the other negatively charged. As the current passes through the film it's pulled back and forth between the magnets, vibrating the air to create sound waves. Compared to traditional dynamic drivers, which use a far simpler a coil of wire and diaphragm that's moved by a magnet, a planar magnetic driver is able to respond to changes in the input signal more quickly, recreating the source material in more detail.

Where a dynamic driver might distort at higher volumes due to the shape of diaphragm distorting as it's pushed and pulled in one spot by a single magnet (often called non-linear distortion), a planar magnetic driver suffers no such issues. That said, they do tend to suffer when it comes to bass response, which is where the dynamic driver excels. In high-end speakers, where similar technology to planar magnetic drivers is deployed, typically the tweeters uses planar magnetic tech or similar, while the woofers use dynamic drivers. That's less of a problem in headphones, where less force is needed to drive bass frequencies, but does highlight why Blue has included a bass boost mode in the Ella amplifier.

I don't think the Ella headphones need a bass boost, but then I prefer my music a little less warm than most. Either way, there's no doubt these are great sounding cans, so long as you feed them a decent sound source. The headphone amp is great for boosting a signal to a level the Ella can work with, but it is just that, a simple boost—if you put rubbish in, you still get rubbish out. The minimum quality is really Spotify's "Extreme" setting, which doles out 320Kbps Ogg files. Such is the detail on offer in Blue's Ella that it's easy to hear that annoying digital sparkle you get from lower-resolution files, although some people are more sensitive to this than others.

The biggest strength of the Ella is in the detail they offer: if you want to hear every dropped guitar pick, every accidental brush of a bow on string, or every second of a long reverb tail, planar magnetic headphones are the way to go. The Ella headphones pair this detail with a warmer sound than you might expect. There's a bump in the mid-bass that sounds pleasing enough, but makes the boosted bass mode a tad bloated. They're versatile too, working just as well with a classic score as they do with a cheeky guitar lick. They're not half bad with dance music either, although serious bass heads will still want to go with dynamic driver headphones for the most oomph.

While there's no doubt the Ella sound excellent, particularly when it comes to conveying that feeling of a live performance, they're hard to recommend outright when there are other headphones out there that do just as good a job, if not better, for less money.

The aforementioned Oppo PM-3 (buy here) are the leaders, offering planar magnetic drivers that—while still requiring some sort of half-decent headphone amp—don't require as much juice as others to drive. At £350 you can pick up the Oppo PM-3 and a portable headphone amp for £100 and still come in under the price of the Ella. They look a lot less ostentatious too.

Then there are more traditional headphones like Sennheiser's open-back HD650 (buy here), which retail for £320 and sound amazing, regardless of price. Or you could opt for in-ears like those from Ultimate Ears, which trade a slightly smaller soundstage for excellent detail and brilliant noise isolation. In a market with this much competition you have to do a lot to stand out, or compete on price. Sadly, Blue's Ella headphones do neither.

The good

Wonderfully detailed sound

Broad frequency response

Feel built to last

Good battery life

The bad

Far too heavy, even for planar magnetic headphones

Love it or hate it design

Poor noise isolation, particularly for closed back headphones

The ugly