JBL UA True Wireless Flash Headphones Review

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 JBL Under Armour True Wireless Flash headphones
• Charging case
• 3x fin sizes
• 3x tip sizes
• USB-A to micro-USB charging cable
• Manuals
• 12-month subscription code for MapMyRun app

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 (2nd generation) Truly Wireless 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.