The WF-SP700N true wireless earphones from Sony have three notable characteristics beyond simply being completely free of cables.
They're also part of Sony's "Extra Bass" lineup of audio products, include noise cancellation, and are intended for sports.
For $179.99, we typically only see one of these features, if any.
Unfortunately, these extras don't make a difference when the audio quality is simply poor to start with.
Design
Available in black, pink, white, or yellow, the WF-SP700N earbuds are resistant to water and intended for the gym.
They ship with three color-coded pairs of eartips in small, medium, and large sizes, and like many of the true wireless earphones we test, the fit is lightweight and exceptionally secure.
Unfortunately, the IPX4 rating is on the low end of the water-resistance spectrum.
The earphones can handle light misting and some sweat, but they can't handle water pressure from a faucet, for instance.
Most gym-focused models are going to be rated IPX6 or higher.
The charging case is compact, rounded at the corners, and features a cool lid that slides to the side rather than flipping up.
It can be tricky to get the earpieces to snap into place—you really have to stuff the eartips and fins inside the case in a way that feels a bit unnatural at first, but the magnetic charging points pull the earpieces in and lock them securely.
Powering the case from empty to full takes three hours, and the earphones take about an hour and a half to fully charge.
You should expect only three hours per charge, which is relatively low even for true wireless standards, but the charging case carries multiple extra full charges.
Controlling the earphones is fairly straightforward.
The noise cancellation and ambient sound modes are controlled by a button on the left earpiece.
This same button, when held in place, controls power and pairing.
Playback, track navigation, call management, and voice assistance are controlled by the right earpiece button.
The right earpiece also houses a larger power/pairing button.
Sony's Headphone Connect app is a bit of a wild card.
The app is capable of behaving well and being useful, but it depends on how well the headphones work with it.
In the case of the WF-SP700N, we found it to be fairly useful.
There are EQ settings you can switch between, but there's no user-adjustable custom setting.
The app is helpful for updates, and you can operate the ambient and noise-canceling audio modes as well, but generally speaking, the functions are easy enough to operate on-ear that it seems almost unnecessary.
The mic offers excellent intelligibility.
Using the Voice Memos app on an iPhone 6s, we could understand every word recorded clearly, with even some added bass depth.
Still, some users will be annoyed by the audio only coming through the left ear during calls—this is par for the course with true wireless earphones, and another reason this category still has some growing pains to move past.
Performance
The noise cancellation circuitry does a laudable job of eliminating low frequency rumble.
So on airplanes and trains, it should help cut out a wide swath of the noise.
For higher frequency sounds, like the whir of a fan or AC unit, the circuitry itself doesn't do much, but the excellent in-ear seal created by the secure-fitting earpieces blocks out so much of the surrounding ambient noise that the NC circuitry hardly needs to do anything more.
This isn't the most effective noise cancellation we've heard, but for the price, it's surprisingly good.
That only makes the rest of this review more deflating.
Moving along to audio performance...it's not good.
Sony manufactures some of the best-sounding headphones on the market, but these earbuds are not in that league.
The problem is not the insanely boosted bass, though that certainly creates an issue of an unbalanced sound signature.
The issue is, bass-heavy sound signature or not, the high frequencies sound dreadful through the WF-SP700N.
Remember the sound of low-bitrate MP3s, with cymbals that sounded like they were underwater or distorting and crackling? Pick a song, any song, and earphones deliver this low-fi sound, ruining nearly any higher register percussion, often affecting vocals as well.
It's so poor, in fact, we thought we had a defective model (we didn't—we tested two units to make sure).
This is the point where I normally discuss how various tracks sound through the WF-SP700N over the course of a few paragraphs, but there is no point—I can sum it up in a sentence.
On tracks with intense sub-bass content, like The Knife's "Silent Shout," or on Bill Callahan's "Drover," a track with far less deep bass in the mix, or on Jay-Z and Kanye West's "No Church in the Wild," or orchestral tracks, like the opening scene from John Adams' The Gospel According to the Other Mary, the powerfully boosted bass cannot overpower the mediocre-at-best sound these drivers and produce when delivering treble, regardless of volume levels.
First, I thought perhaps the battery power was low and this was affecting the audio.
It wasn't.
I then considered that it could be something with the noise cancellation, but in all three modes (on, ambient, and off), the audio remained poor.
I powered Bluetooth off on my source device, powered it down, and initiated pairing again—to no change in performance.
When I contacted Sony for comment on my findings, a spokesperson responded, "At Sony, great sound quality is of paramount importance.
We stand behind the sound quality of the WF-SP700N headphones, which provide users a distraction-free, wire-free experience."
Conclusions
Obviously, the fairly solid noise cancellation is rendered insignificant by the WF-SP700N's poor audio performance.
With zero hyperbole, I can name 30 pairs of wireless—and some true wireless—in-ears that sound far better than this, and most of them are also less expensive.
But life is short, so I'll tell you that in the relatively new field of true wireless earbuds, our favorites so far are the Bose SoundSport Free and the JLab Epic Air.
Neither pair is flawless, but both deliver solid audio at the very least.
If it's excellent in-ear noise cancellation you're after, the wireless Jabra Elite 65e earphones are only barely more expensive and do a great job, while the pricier Bose QuietControl 30 are still the best wireless noise-canceling in-ears we've tested, but neither of these are true wireless pairs.
Sony has created some excellent-sounding headphones and speakers, so we'll just chalk this up to a swing and a miss.
The Bottom Line
Sony's WF-SP700N true wireless earphones are a rare misstep from a company that typically has much higher standards.
