JBL and Under Armour bill their new True Wireless Flash ($170) as totally wireless sports earphones "designed for runners by runners." They're technically the first truly wireless earphones from the duo and as far as truly wireless sports earphones go, they're quite good, although some of their allure is tempered by a rather large charging case that's probably three times the size of Apple's AirPods' charging case.
UA True Wireless Flash
The Good
The Bad
The Bottom Line
The first thing you'll noticed about the earphones -- and the "rugged aluminum" charging case -- is they have some heft to them. By that I mean they feel solidly built, and in the case of the earphones, while they aren't heavy per se, they certainly weigh more and are bigger than the AirPods. The charging case is a little heavy, weighing in at 4.2 ounces (118 grams) with the earbuds inside.
The buds in their charging case.
These being sports earphones, they include three different-sized sports fins and tips (JBL calls them "Flex Ear Tips") to help lock the buds in your ears with a tight seal to maximize sound quality. I achieved a good fit with the medium fins and large tips and I found the buds fit comfortably and securely. I was able to run with them without a problem and they performed well with minimal Bluetooth hiccups in New York City, which is filled with wireless signals that can cause interference problems for lesser true wireless earphones.
The earphones are equipped with 5.8 millimeter drivers and are fully waterproof, with an IPX7 rating, which means you can submerge them in 3 feet/1meter of water for up to 30 minutes. (No, you can't swim and listen to music with them -- Bluetooth doesn't transmit through water.)
I thought they sounded decent -- on par with and even slightly better than other true wireless headphones in this price class. They sounded well-balanced, with fairly natural sounding mids and meaty bass that's pretty well defined (read: not boomy). You're dealing with Bluetooth streaming so you're not going to get as clean or detailed sound as you would with a good pair of wired headphones, but most people should be pleased with the sound quality.
What you get in the box.
Like a lot of true wireless headphones, battery life is rated at 5 hours and you get four additional charges from the battery case.
As I said in the intro, these are designed with runners in mind. The UA True Wireless Flash features something marketed as "Bionic Hearing," a "unique sound and mic technology, enabling athletes to hear surroundings with two sound technologies: TalkThru and AmbientAware." It's similar to other "transparency" modes found on other headphones and earphones, so I'm not sure how unique it is, but it's useful enough.
With TalkThru Technology, your music is lowered and speech is amplified when you touch the button on the outside of the left bud. Tap it again and your music volume returns to the previous level.
Flex Ear Tip.
Double-tap that same left earbud and the earphones go into AmbientAware mode. That allows sound from the outside world to leak into your ears through the earphones (background noises are amplified) so you can, say, hear traffic better around you. Of course, it helps to turn down the volume of your music if you really want to hear the outside world.
Under Armour throws in a 12-month MapMyRun Premium membership ($30 value) with the purchase of the earphones. MapMyRun, which Under Armour acquired in 2013, allows members to track and analyze advanced gait metrics like cadence, stride length, distance, pace and splits. When running the app, you get that info piped into the earbuds.
As for other controls, tapping the button on the right bud pauses your music and double-tapping it advances the track forward. Holding the button down on the left earbud calls up your voices assistant (Siri if you're using an iPhone or Google Assistant if you're using an Android device).
The Flash's charging case (top) vs. the charging cases of the Anker SoundCore Liberty Air (left) and Apple AirPods (right).
You might get slightly better call performance from Jabra's Elite 65t, which lists for the same price as this headphone, but overall The Flash worked well for making calls.
Sound-wise, the Flash is arguably slightly better-sounding, with superior bass performance in particular. However, the Jabra, which doesn't have sports fins (but still manages to stay in most people's ears securely) is the more comfortable earphone. It's just a little smaller and you feel it in your ears a little less. Of course, with these types of in-ear headphones, their fit varies from person to person and some earphones just won't be a good match for your ears.
While the Flash also sounds a little better than Anker's SoundCore Liberty Air, that model is less than half the price and lighter, too. The Flash is presumably more durable and sweat resistant and should hold up better over time, but the Flash's large charging case is definitely a little irritating. It's not necessarily a deal-breaker but it's something JBL is going to have to engineer better for the next iteration.
The UA Flash is a top-end model part of JBL's 2019 true wireless lineup that also includes the JBL Endurance Peak, Tune 120TWS and the Reflect Flow, which seems similar to the Flash but costs $150. While the Flash is currently available, the rest of the new models ship this spring.
Read more: JBL introduces 4 new true wireless headphones at CES 2019