The JBL UA True Wireless Flash are great sports headphones that stand out thanks to their good audio reproduction and their rugged build quality. They're versatile for a wide variety of music genres, are sweat-proof and waterproof, and their bulky design feels durable for most intense sports. Their fit is good and fairly comfortable, on top of sealing off ambient noise, making them well-rounded for most everyday uses. Unfortunately, they won’t be great for watching videos due to their very high latency, and some may feel like four hours of battery life isn’t enough for a single charge. On the upside, they also offer a 12-month subscription for Under Armour’s fitness app called MapMyRun.
The JBL Under Armour True Wireless Flash are decent for mixed usage. They have good audio reproduction for in-ears, and their small design is easy to carry around in your commute or at the gym. They also create a good seal in your ears, which isolates a good amount of ambient noise, which is good for public transit or at the office. They're designed as sports headphones thanks to their stability fins and waterproof build. They don’t have the longest battery life for flights or a normal workday, but they’ll be fine for working out. However, their latency is very high, and you shouldn't use them for watching video content and gaming.
The JBL Under Armour True Wireless Flash are alright for neutral sound. These in-ears have a good audio reproduction with excellent bass range and mid-range and a good treble. Their bass is slightly thumpy, but some may prefer this. Vocals and leads are accurately reproduced, but they could feel ever-so-slightly nudged to the back of the mix for some. They're very versatile for a wide variety of music genres, but their treble is slightly uneven, which some may not hear. The in-ear fit might not be ideal for long neutral listening sessions as some may feel discomfort after a while.
The JBL Under Armour True Wireless Flash are good for commuting. Their fit blocks out a good amount of ambient noise, including the deep rumble of bus and plane engines. They’ll be a good option for public transit, and since they barely leak, you can mask even more noise by raising your listening volume. Additionally, they're easy to carry around thanks to their portable design, but they don’t have very long battery life on one charge, which won’t be the best option for long rides and flights.
The JBL Under Armour True Wireless Flash are great for sports. They're designed for working out and will be suitable for most sports. They fit securely inside the ear and don’t move much when being active. Their stability fins will help keep them in place, and since you get different size options, you can find the most stable one for you. They also don’t trap heat inside your ears, meaning you shouldn’t sweat more than usual when wearing these during your workouts.
The JBL Under Armour True Wireless Flash are decent for the office. They do a great job blocking out work environment noise like ambient chatter and fan noises like A/C systems. They also barely leak, so you shouldn’t bother surrounding colleagues with what you’re listening to. However, their battery life won’t be long enough for you to use them during a full workday; you’ll need to charge during lunchtime. Also, the in-ear fit might not be the best to wear for a few hours, as some may feel discomfort.
The JBL Under Armour True Wireless Flash are bad for gaming. The microphone won’t be good enough for online gaming, and their latency is too high for video games. The delay between sound and video will be too noticeable and won’t be suitable for this use. They also don’t have good battery life, and overall, will be a very poor choice for gaming.
The JBL Under Armour True Wireless Flash have a bulky in-ear design that protrudes quite a bit out of the ears. They look like sports earbuds with their stability fins and have Under Armour logos on the back of the buds, which act as buttons. They only come in a single all-black color scheme, with a small red accent.
The JBL Under Armour True Wireless Flash are decently comfortable truly wireless headphones. They're lightweight, even if they have a bulky design. They fit nicely inside the ears and come with a few options for tip and fin sizes to help you find the most comfortable fit. Some people may not like the in-ear fit and may feel ear fatigue after a while, but these don’t enter the ear canal as deeply as traditional in-ears, thanks to their angled design. If you want a pair of truly wireless in-ears that are even more comfortable, check out the JBL LIVE 300TWS Truly Wireless.
The JBL Under Armour True Wireless Flash have sub-par controls. Each bud has an Under Armour logo that is also a button. On the right ear, you can play/pause your music and skip tracks, but you can’t rewind or go to the previous track. You can also manage calls and mute your microphone. On the left earbud, you can cycle through their ambient and talk-through modes. A single tap will put you in their talk-through mode, which greatly reduces your music level and lets you hear surrounding noise very well. A double-tap will put you in their ambient mode, which will allow you to hear your surroundings, but you can still hear your music fairly loud.
Unfortunately, you can’t jump from one mode to another and need to go back to their normal listening mode before making another input. You can also trigger your device’s voice assistant with a two-second hold on the left earbud. Unfortunately, they don't have any volume controls like other sports truly wireless headphones like the Bose SoundSport Free Truly Wireless.
Like most in-ears, the JBL UA Flash True Wireless are very breathable headphones, even if their design is quite bulky. They block most airflow inside your ear canal, but their in-ear design will still be breathable and won’t trap too much heat. You shouldn’t feel a big difference in temperature when wearing these during your workouts, and they won’t make you sweat more than usual.
Like most truly wireless headphones, the JBL Under Armour True Wireless Flash are very portable. The buds are a bit bulky, but they will still easily fit inside pockets or a bag. They're easy to carry around and come with a nice hard case that is fairly portable, too.
These headphones come with a hard charging case that protects the headphones well against physical damage, water exposure, and scratches. The case is a bit bulky but should still fit in most pockets or a bag. It has a high-end feel as it is heavy and made from solid materials. Unfortunately, it has some minor flaws. The tray wiggles around when fully extended, and the earbuds sometimes clip the top of the case when pushed back in. The case is said to be waterproof, and you also get LEDs for battery level indication.
The JBL Under Armour Flash True Wireless are very well-made, truly wireless headphones. The buds are dense and feel solid enough to survive a few accidental drops without too much damage. They feel like premium headphones, similar to the Sennheiser Momentum True Wireless. Their metal case is also very well-made and feels sturdy. These headphones are certified IPX7 for water resistance.
The JBL Under Armour True Wireless Flash are very stable and will be suited for most sports. They're somewhat bulky but still sit nicely inside the ears and don't move much, even when exercising. They have a few size options for tips and fins, which helps you find the perfect fit. You should be able to do most sports with these without them popping out of your ears. Also, their truly wireless design means you won’t have to worry about any cables.
The frequency response consistency is fantastic. If the user can achieve a proper fit and an air-tight seal using the assortment of tips that come with them, they should get consistent bass and treble delivery every time they use the headphones.
The JBL True Wireless Flash's bass performance is outstanding. The LFE (low-frequency extension) is down to 10Hz, which is excellent. Their response is virtually flawless and follows our target curve very well. It has a small overemphasis in the low-bass range, which results in a slight excess of thump and rumble, which fans of bass-heavy music may prefer. Overall, their bass is amazing and has the right amount of punch and body without being overly done.
Their mid-range is fantastic. The response throughout the range is very well-balanced and flat, which results in an accurate reproduction of vocals and lead instruments.
The JBL UA True Wireless Flash have mediocre treble accuracy. It's not as bad as the Monster Clarity 101 AirLinks Truly Wireless, but the broad dip throughout the range negatively affects the brightness and detail of vocals and instruments.
The stereo imaging is amazing. Their weighted group delay is at 0.16, which is very low. The group delay graph also shows that the entire response is well below the audibility threshold. This ensures a tight bass and a transparent treble reproduction. Also, the L/R drivers of our test unit were well-matched in frequency, amplitude, and phase response. This is important for the accurate placement and localization of objects (voices, instruments, video game effects) in the stereo image. Note that these results are only valid for our unit, and yours may perform differently.
The soundstage is poor. This is because creating an out-of-head and speaker-like soundstage is largely dependent on activating the resonances of the pinna. The design of in-ears and earbuds is in such a way that fully bypasses the pinna and doesn't interact with it. Also, because these headphones have a closed-back enclosure, their soundstage won't be perceived to be as open as that of open-back earbuds like the Apple AirPods 2 Truly Wireless 2019 or the Bose SoundSport Free Truly Wireless.
The JBL UA True Wireless Flash have a great noise isolation performance. They only passively block noise as they don’t have an ANC feature. In the bass range, occupied by the rumble of airplane and bus engines, they reduce the noise by about 11dB, which is decent. However, this is rather impressive for in-ears and more than what some active noise cancelling headphones achieve. In the mid-range, important for blocking out speech, they achieved 20dB of isolation, which is very good. In the treble range, occupied by sharp S and T sounds and fan noises like A/C systems, they achieved about 46dB of isolation, which is excellent.
The leakage performance is outstanding. These in-ears don't leak much, so you don't need to worry about disturbing people around you unless you are blasting your music in a very quiet room. With the music at 100dB SPL, the leakage at one foot away averages at 23dB SPL and peaks at 29dB SPL outside of the bass range, which is noticeably quieter than the noise floor of an average office.
The recording quality of the microphone is okay. Speech recorded or transmitted with the microphone will sound thin and muffled. This is due to LFE (low-frequency extension) being at 265Hz and the HFE (high-frequency extension) being at 3.5kHz. However, the limited high-frequency extension is a limitation of the Bluetooth protocol and is a problem with all Bluetooth microphones. However, speech will still be decently intelligible with this microphone in quiet environments.
The microphone is mediocre at noise handling. In our SpNR test, it achieved a speech-to-noise ratio of 16dB, indicating that it's best suited for quiet environments. But it won't be ideal for moderate and loud environments, as it will have difficulty fully separating speech from ambient noise.
The JBL Under Armour True Wireless Flash offer just over four hours of continuous playback with one charge. They take about an hour and a half to fully charge, and you can expect about 20 additional hours of playback from the case, according to the specs sheet. Unfortunately, they don’t have a smart power-saving feature, so be sure to turn the headphones off or put them back in their charging case if you’re not using them.
These headphones don’t have a dedicated companion app for customization options. However, when buying them, you get a 12-month subscription code to Under Armour’s MapMyRun fitness app.
The JBL Under Armour True Wireless Flash are Bluetooth compatible but can’t be connected to multiple devices at once. This means you can't switch between your work computer and your phone. They also don’t support NFC for a quicker and easier pairing procedure.
The latency is very high. It's noticeably higher than most Bluetooth headphones, and most people will see an important delay between audio and video. This means you shouldn’t use them for watching videos or gaming.
Like expected, you can't use the JBL Under Armour True Wireless Flash headphones wired.
These truly wireless headphones come with a hard charging case that has a USB input to power the case but doesn’t have any other inputs. It offers about 20 additional hours of battery life, according to the specs sheet.
The JBL Under Armour True Wireless Flash are good sports headphones that set themselves apart by their great build quality and audio reproduction. They're also comfortable for in-ears. However, their latency is very high, and some may feel like four hours of battery life isn’t enough.
See our recommendations for the best wireless Bluetooth earbuds for running and working out, the best Bluetooth earbuds, and the best true wireless earbuds.
The JBL UA True Wireless Flash and the Jaybird Run XT Truly Wireless are both great sports headphones, but the JBL might have a small edge over the Jaybird for people who want great performance out of the box. They have a better default sound profile, but they don’t have an app with an EQ that can let you customize their sound signature like the Jaybird. On the other hand, you’ll get a battery performance out of the Jaybird, but their control scheme is more limited and harder to use as you need to push the buds inside your ear canal even more, which can be uncomfortable.
The JBL UA True Wireless Flash are better headphones than the Sony WF-SP700N Truly Wireless. They have better audio reproduction, are more stable for sports, and even if the Sonys are ANC headphones, the JBL have a better isolation performance. The JBL control scheme is easier to use and their build quality feels more high-end, on top of being rated IPX7. They also have about twice the battery life of the Sony. Overall, the JBL are better in almost every aspect, but they don’t support NFC like the Sony do.
The JBL UA True Wireless Flash are better sports headphones than the Jabra Elite Sport Truly Wireless. They are more comfortable and more stable for most sports. They also have a better audio reproduction and are also more versatile for different uses, thanks to their better isolation performance. On the other hand, they don’t have volume controls like the Jabra do, which may be a deal-breaker for some. The Jabra also have a companion app, although the options and controls are limited. Also, our Jabra unit had a noticeable mismatch between the drivers.
The JBL UA True Wireless Flash are better headphones than the Bose SoundSport Free Truly Wireless for most. The JBL are more versatile thanks to their closed-back design that isolates well against ambient noise. They’ll be a better option for commuting, but as sports headphones, it comes to preference. Outside runners might prefer the semi-open design of the Bose to stay aware of their surroundings. The Bose earbud design is also a bit more comfortable, and they have better sound quality and a slightly better battery. On the other hand, you’ll get better range with the JBL, and they have a better microphone for calls. Their case is also more portable and sturdier, on top of being waterproof.